ben m
Joined: 15 Sep 2002
Posts: 337
Location: UK |
| Week 9 - Sequencers |
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Ok, here are the MIDI & Sequencer questions for this week.
01-What is a MIDI sequencer?
02-What are the advantages of hardware sequencers?
03-What are the advantages of software sequencers?
04-What is a piano roll editor?
05-What is a 'drum map'?
06-What is usually seen in the 'arrange' window?
07-What are Tempo/Meter maps?
08-What is the purpose of quantizing?
09-What is Groove Quantizing and how does it work?
10-Explain Note On quantizing.
11-Explain Over Quantizing.
12-Explain Iterative Quantizing.
13-What do quantize values such as 4,32,16T etc represent?
14-What is the score editor and how does it display musical information?
15-How, and using what protocol, may a Sequencer be synchronised to a multitrack recorder?
16-If you change the tempo of the song, what will happen to (a) the MIDI parts? (b) the Audio parts?
17-How does the application Recycle allow MIDI to control Audio parts?
18-What is OMS?
19-How does OMS simplify MIDI studio setups?
20-What's the difference between type 0 & 1 MIDI sequences?
21-Why are there 'virtual' MIDI ports available (i.e. Hubis Loopback)?
22-What is the 'rewire' protocol?
23-What is the rocket networks protocol and how does it work?
24-What are step sequencers?
25-Why are step sequencers usually more suitable for percussion & drum parts?
26-Why are click tracks important functions in MIDI/Audio sequencers?
27-Why do many sequencers metronomes allow either Audio or MIDI clicks?
28-How is MIDI data such as modulation and pan usually displayed in part editors?
29-How many times is master clock transmitted per quarter note?
30-What are the functions of the master and slave in any synchronisation situation?
31-What timing division does SPP (song position pointers) work on?
32-What is MIDI Sync mode and what synchronisation protocols does it accept?
33-What is the primary difference between MIDI Time Code and MIDI Clock, and why is MTC more accurate?
34-Define the basics of SMPTE?
35-What similiarities are there between SMPTE and MTC?
36-How does FSK work?
37-Does standard-FSK synchronisation give any indication of song position?
38-What improvements does Smart-FSK offer over standard FSK?
39-If using FSK with analogue tape, why must the speed of the tape not change after recording the FSK timing information?
40-What is the 'tempo master' and what is the 'transport master' within a MIDI synchronised setup?
41-What problems may arise from extensive use of controller data within a MIDI piece?
42-Name 2 different connection protocols for MIDI interfaces?
43-Can tempo changes and time signature changes be made during a song within a sequencer?
44-What considerations must be made when using a software sequencer as part of a live show?
Good Luck.
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ben@audiocourses.com |
Tue May 04, 2004 4:28 pm |
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hoggs33
Joined: 09 Feb 2004
Posts: 55
Location: Nottingham, England |
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01-What is a MIDI sequencer?
MIDI sequencer could be hardware or software and allows multi-part music to be created, edited, stored and played back (via a MIDI interface)
02-What are the advantages of hardware sequencers?
They provide a one box solution to sequencing, they are generally more reliable than computers in live situations or when being moved from studio to studio, although they tend to have fewer editing options than software sequencers, they are generally easier to use and you don’t have to learn how to use a computer before you can begin to learn your sequencer software.
03-What are the advantages of software sequencers?
They have a good visual interface, provide more comprehensive editing facilities, you are not ties to one manufacturer – if a better program comes out then you can always move over to it, most computer sequencers support multiple MIDI output ports via special multi-port MIDI interface and professional standard score printing is available in many sequencing packages.
04-What is a piano roll editor?
The piano roll is a horizontal grid with piano keys don the left side to identify notes. Small blocks representing individual notes are displayed on the grid. The length of each block represents the duration of the note. Often, there is an additional graphic that displays the velocity of each note and allows it to be edited.
05-What is a 'drum map'?
A drum map is a graphical representation of General MIDI drum sounds relative to the notes on a keyboard and the corresponding note number.
06-What is usually seen in the 'arrange' window?
This window would usually display all the tracks (both MIDI and audio) as well as any effects, panning etc. It gives a general overview of the parts of a song.
07-What are Tempo/Meter maps?
These contain info about any tempo changes within a song.
08-What is the purpose of quantizing?
To ‘correct’ the timing of notes played into a sequencer. Inaccurately timed playing can be aligned precisely to bars and beats.
09-What is Groove Quantizing and how does it work?
This is one technique of quantizing that attempts to retain a human feel. Notes are aligned according to a grid that is not actually strict eight notes or sixteenth notes, but subtly different in-between positions that give a nice feel to the playing.
10-Explain Note On quantizing.
This moves the beginning of the note to the nearest bar etc depending on the quantize settings but leaves the end of the note where it is.
11-Explain Over Quantizing.
I could only find info on this relative to Cubase in respect of which Steinberg say that over quantizing is the most plain musical one as it moves the notes to the closest Quantise value. They also claim it ill detect whether you constantly play behind or ahead of the beat.
12-Explain Iterative Quantizing.
This works in stages. It moves the notes towards the selected Quantize value according to a strength parameter that is set previously. Certain notes can be excluded by setting a number of ticks (between 0 and 96) that a note can differ from the quantize position without being moved.
13-What do quantize values such as 4,32,16T etc represent?
Note values such as quarter notes, sixteenth notes etc.
14-What is the score editor and how does it display musical information?
The score editor shows the sheet music representation of the part that has been played/recorded – this can be edited or printed out for a ‘hard copy’ of the score etc.
15-How, and using what protocol, may a Sequencer be synchronised to a multitrack recorder?
By using SMPTE timecodes of smart FSK codes recorded to a spare track on the recorder.
16-If you change the tempo of the song, what will happen to (a) the MIDI parts? (b) the Audio parts?
The MIDI parts would speed up with any increase in tempo or slow down with a decrease in tempo. The audio parts would still play back at their original tempo therefore resulting in them being out of time with the MIDI parts.
17-How does the application Recycle allow MIDI to control Audio parts?
Audio parts are broken down into small segments (Rex files?) so that the audio can then follow MIDI in changes of tempo without the pitch being altered.
18-What is OMS?
OMS stands for Open Music System created by Opcode. It is the standard for MIDI management. It provides detailed description that define studio setups.
19-How does OMS simplify MIDI studio setups?
It can display and edit your MIDI set up on screen with colourful icons that illustrate connections to MIDI interfaces, sound cards and instruments. OMS also allows access to your studio by instrument and patch name. It only has to be set up once for all MIDI applications, it provides factory names for over 100 devices and recognises SampleCELL.
20-What's the difference between type 0 & 1 MIDI sequences?
Type 1 files contain separate information for each track. With type 0 files, all the tracks are merged into a single track, although MIDI channel information is still retained.
21-Why are there 'virtual' MIDI ports available (i.e. Hubis Loopback)?
Such virtual MDID ports are used when a soft synth does not come with its own MDID driver. In such cases a virtual MIDI router is used, sometimes called a MIDI loopback driver, to create the internal routing that would be needed. The most popular is Hubi’s MIDI Loopback Device.
22-What is the 'rewire' protocol?
Rewire is a technology for transferring audio data between software application, in real time, the software equivalent of a multi channel audio cable.
23-What is the rocket networks protocol and how does it work?
This was launched by Steinberg to create a virtual studio online to which musicians can gain access live over the internet to enable them to work together and share projects.
24-What are step sequencers?
Notes are played in one at a time with step sequencers – rather like typing a letter with one finger. The ‘programmer’ decides where the notes go and how long they will be and they can then be played back at any tempo.
25-Why are step sequencers usually more suitable for percussion & drum parts?
Drum parts in general tend to be more repetitive than other parts so not as many steps need to be programmed. Drums also have a lot of fixed note values and so it is easier to use step sequencers for programming. It also ensures that the drums and programmed exactly in time.
26-Why are click tracks important functions in MIDI/Audio sequencers?
In order to allow the musician to play their part in time with the track and other recorded instruments so that everything plays back at the same tempo.
27-Why do many sequencers metronomes allow either Audio or MIDI clicks?
So that the user can choose which sound is used to produce the metronome if using MIDI clicks so that a more user friendly or appropriate sound can be used relative to the preferences of the performer.
28-How is MIDI data such as modulation and pan usually displayed in part editors?
As a numeric value between 0 and 127
29-How many times is master clock transmitted per quarter note?
24 times.
30-What are the functions of the master and slave in any synchronisation situation?
The master controls the slave, therefore all items such as tempo will follow the setting of the master unit.
31-What timing division does SPP (song position pointers) work on?
16th beats.
32-What is MIDI Sync mode and what synchronisation protocols does it accept?
MIDI sync mode needs to be set on the slave device in order for it to be controlled by the master. It accepts MTC and MIDI clock protocols.
33-What is the primary difference between MIDI Time Code and MIDI Clock, and why is MTC more accurate?
MIDI clock does not contain song position information. MTC contains song position info and therefore keeps in sync much better throughout a song and is therefore more accurate.
34-Define the basics of SMPTE?
SMPTE stands for the Society of Motion Picture and Television Engineers. This is a timecode that identifies each frame of a video recording with a unique number in terms of hours, minutes, seconds and frames.
35-What similiarities are there between SMPTE and MTC?
MTC (MIDI Time Code) is basically SMPTE timecode adapted for use in a MIDI system. MTC uses the address part of SMPTE i.e hours, minutes, second and frames, but not the clock.
36-How does FSK work?
FSK is a type of modulation used for digital data and stands for Frequency Shift Keying. This records a series of electronic tones onto a spare track. These tones are related to the tempo clock of the device , so as the tempo is increased, the electronic sync track follows.
37-Does standard-FSK synchronisation give any indication of song position?
No – any track would have to started from the beginning if stopped part way through in order for the sync to be re-established.
38-What improvements does Smart-FSK offer over standard FSK?
This still works by recording code to tape in the form of tones, but is designed to work with MIDI Song Position Pointers so that the tape machine can be started anywhere in the song and the sequencer will always find the right place.
39-If using FSK with analogue tape, why must the speed of the tape not change after recording the FSK timing information?
Because the sequencer would then not be in sync with tape.
40-What is the 'tempo master' and what is the 'transport master' within a MIDI synchronised setup?
System command messages that control the timing and transport operation. Tempo obviously controls the tracks tempo and the transport controls start, stop etc messages.
41-What problems may arise from extensive use of controller data within a MIDI piece?
Likely to impose too greater load on the CPU and result in latency and porr quality playback.
42-Name 2 different connection protocols for MIDI interfaces?
USB, Firewire.
43-Can tempo changes and time signature changes be made during a song within a sequencer?
Yes
44-What considerations must be made when using a software sequencer as part of a live show?
A click track may need to be provided to any other performers, particularly the drummer who would need to p lay in time with the track, including count in beats etc. All other relevant instruments would need to be synced to the sequencer. The sequencer would also need to be very reliable and stable as if it fails this could disrupt the whole performance – some sort of backup would be advisable. |
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Thu May 06, 2004 7:04 pm |
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iNSTiNCT2765
Joined: 05 Nov 2003
Posts: 60
Location: Denmark |
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Week 9 – Sequencers
01-What is a MIDI sequencer?
A MIDI sequencer handles MIDI data from many different channels and stores musical performances so they can be played back They can duplicate a musician’s performance exactly and are used for song composition.
02-What are the advantages of hardware sequencers?
Hardware sequencers may come included in a sampler/drum machine or a keyboard workstation like the MPC1000 and the Korg Triton respectively. The advantage of this is that it eliminates the need for a computer to be added to your set up and makes matters less confusing. Hardware sequencers are also less confusing than software sequencers due to the limited amount of editing that can be done. The MPC1000 is a small drum machine with its own sequencer built in so the music can be sequenced right in the box. This is good for live performances.
03-What are the advantages of software sequencers?
Software sequencers add a visual aspect and for people who aren’t very musical, this can be a very big aide. With the hardware sequencers, it is more about catching a nice performance and working from there but with a software sequencer, it is much easier to identify wrong notes or timing faults and correct them. Software sequencers also have a lot more editing options and other functions that hardware sequencers do not such as score printing and the incorporation of audio data.
04-What is a piano roll editor?
A piano roll editor is a window in which the notes can be edited with a mouse. The notes of the keyboard run down the vertical line and time runs through the horizontal. For example, if you have recorded a 4 bar piano riff, it would show the notes from left to right as they are played for the four bars. The length of the notes represents the duration and can be changed by making the length longer or shorter. If you have played a wrong note but is pleased with the rest of the performance then that individual note can be moved up or down to a desired note or erased all together.
05-What is a 'drum map'?
A drum map shows the layout of different drum sounds in General MIDI. Different note numbers from 35-81 represent different types of drum sounds.
06-What is usually seen in the 'arrange' window?
The ‘arrange’ window gives a clear visual interpretation of the layout of all the tracks you are working with, both audio and MIDI. The tracks are stacked one on top of the other and move across a timeline from left to right. The ‘arrange’ window is the place where the arrangement of all the data is done when building a composition.
07-What are Tempo/Meter maps?
The Tempo/Meter maps contain timing and tempo information and any changes of tempo that might occur during the course of the song.
08-What is the purpose of quantizing?
The purpose of quantizing is to correct the timing and duration of notes. It moves them to the closest specified note (1/4 note, 1/8 note etc.)
09-What is Groove Quantizing and how does it work?
Groove Quantizing helps restore some of the human feel to recorded material because instead of quantizing to fixed intervals, it uses a time grid based on a pre-recorded rhythmic pattern that can contain timing, note duration and velocity information.
10-Explain Note On quantizing.
Note On quantizing moves the start of the note to the nearest quantizing grid value but leaves the end of the note untouched.
11-Explain Over Quantizing.
Over quantizing just moves the note to the set timing grid without adding a groove or human feel to it.
12-Explain Iterative Quantizing.
Iterative quantizing moves the notes closer to the closest note in the defined timing grid by a set percentage.
13-What do quantize values such as 4,32,16T etc represent?
They represent the note grids to which the quantizing will move the notes (1/4, 1/32, 1/16 triplet)
14-What is the score editor and how does it display musical information?
The score editor displays the musical information as standard musical notation. This sheet music can then be printed and used for live performances of your compositions.
15-How, and using what protocol, may a Sequencer be synchronised to a multitrack recorder?
A sequencer can be synchronised to a multitrack recorder using MIDI Time Code (MTC).
16-If you change the tempo of the song, what will happen to (a) the MIDI parts? (b) the Audio parts?
The MIDI parts will play at the tempo selected, assuming that they are one hit notes and not loops, without any problem but the audio parts will play at their current tempo.
17-How does the application Recycle allow MIDI to control Audio parts?
Recycle is a program that slices up audio and then it can be saved as small chopped bits or as a Rex file. The Rex file can then be imported into a sequencer and is then also locked to the tempo of the sequence.
18-What is OMS?
OMS stands for Open Music System and is developed by Opcode. It is a way of managing all you MIDI set-ups on your PowerMac.
19-How does OMS simplify MIDI studio set-ups?
It displays your MIDI set-ups on screen and all your connections to MIDI interfaces, soundcards and instruments. They can also be edited right there.
20-What's the difference between type 0 & 1 MIDI sequences?
Type 0 MIDI sequences carry the entire MIDI on one single track while type 1 MIDI sequences use multiple tracks.
21-Why are there 'virtual' MIDI ports available (i.e. Hubis Loopback)?
Virtual MIDI ports are available for software that doesn’t have its own MIDI driver. MIDI drivers like Hubis Loopback are then used to do the internal routing that is needed.
22-What is the 'rewire' protocol?
The ReWire protocol, developed by Propellerheads, is a system for transferring audio data between two computer applications. It is like an invisible cable that streams audio from one software program into another.
23-What is the rocket networks protocol and how does it work?
Steinberg developed the Rocket Networks protocol and it is a way of working with other musicians on the same project over the Internet.
24-What are step sequencers?
A step sequencer is a pattern grid set to a specific length, for example 2 bars, with each channel in it having it’s own sample loaded onto it. In software sequencers, the notes can then be clicked in where desired on any beat. This can be used to make drum loops. A good example of a software step sequencer is Fruity Loops.
25-Why are step sequencers usually more suitable for percussion & drum parts?
This is because percussion and drum parts are usually the most repetitive elements in a song and they can be repeated over and over using a step sequencer. It is also very easy and accurate in terms of timing to click in a rhythm pattern in a step sequencer.
26-Why are click tracks important functions in MIDI/Audio sequencers?
Click tracks are important for the musicians to catch the tempo of the track and play their parts to it.
27-Why do many sequencers metronomes allow either Audio or MIDI clicks?
This is so you have the option of using a MIDI click or a desired sound of your own that you find more suitable or comfortable with as a metronome.
28-How is MIDI data such as modulation and pan usually displayed in part editors?
They are displayed as a value between 0-127 over the specified time (length of the sequence).
29-How many times is master clock transmitted per quarter note?
Master clock is transmitted 24 times per quarter note.
30-What are the functions of the master and slave in any synchronisation situation?
The master device controls the tempo, start playback and stop playback and the slave follows these settings.
31-What timing division does SPP (song position pointers) work on?
16th notes
32-What is MIDI Sync mode and what synchronisation protocols does it accept?
MIDI Sync mode is a way of synchronising two or more MIDI devices and where one acts as the master and the others are the slaves. MIDI Sync accepts MIDI Clock and MIDI Time Code and Smart FSK (frequency shift keying) protocols.
33-What is the primary difference between MIDI Time Code and MIDI Clock, and why is MTC more accurate?
The primary difference between MTC and MIDI Clock is that MTC uses real time (hours, minutes, seconds, frames) and is not related to the tempo or beats and bars. This makes it more accurate because every device is locked into the same 24-hour clock. MTC also contains song position data continuously to make up for differences that might occur between the master and the slave. This positional data is sent in short burst (four per frame). It takes 8 of these messages to complete the positioning data meaning that the receiving MIDI device needs to read two frames before it gets the complete positioning information. So the positioning information is updated every two frames. MIDI Clock messages don’t carry song position pointers so MTC is much more accurate.
34-Define the basics of SMPTE?
SMPTE stands for Society of Motion Picture and Television Engineers and it is an industry standard for linking video and audio equipment together in sync. It works by striping an audio channel of a multitrack tape with a Sync Tone that is used to synchronise the multitrack with other equipment. It uses a real time 8-digit 24-hour clock.
35-What similarities are there between SMPTE and MTC?
MTC is based on the principles of SMPTE and both use a real time 24-hour clock for synchronising all connected devices.
36-How does FSK work?
Frequency Shift Keying is tempo relative and uses two distinct tones to form a signal. One is put on tape and the other tone marks the occurrence of a clock signal. The sync device then generates a clock signal every time there is a transition from the first tone to the second one.
37-Does standard-FSK synchronisation give any indication of song position?
No, FSK can only sync up at the beginning of a sequence.
38-What improvements does Smart-FSK offer over standard FSK?
Smart-FSK offers song position pointers for synching up at any point of the sequence.
39-If using FSK with analogue tape, why must the speed of the tape not change after recording the FSK timing information?
Because the timing sent from FSK to tape is final and cannot be changed after it has been striped.
40-What is the 'tempo master' and what is the 'transport master' within a MIDI synchronised set-up?
The computer with the sequencer would be the ‘tempo master’ and the multitrack tape recorder would be the ‘transport master’.
41-What problems may arise from extensive use of controller data within a MIDI piece?
Extensive use of controller data could cause latency issues depending on your CPU speed. Note dropouts could also occur because of the maximum polyphony being reached in the MIDI module.
42-Name 2 different connection protocols for MIDI interfaces?
Firewire and USB
43-Can tempo changes and time signature changes be made during a song within a sequencer?
Yes they can.
44-What considerations must be made when using a software sequencer as part of a live show?
If there are band members who play live instruments then they have to have some sort of click track available to them so they can play to tempo. This can be fed to them through headphones. You should also make sure the sequencer is stable and the computer is able to handle the job and not suddenly freeze up and need to be rebooted. You should also have a backup plan for the worst case scenario. A CD with the mixdown of all the sequencer music would be ideal. |
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Fri May 07, 2004 9:00 pm |
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griff505
Joined: 23 Feb 2004
Posts: 68
Location: Bristol |
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01-What is a MIDI sequencer?
A MIDI sequencer is a digital device used to record, edit and output MIDI messages in a sequential fashion. The sequential messages are arranged in a track-based format that follows the modern production concept of locating separate instruments onto separate tracks. The ‘Tracks’ contain MIDI related performance and control events that are made up of such channel and system messages as note on/off, velocity , modulation , aftertouch, and program / cc messages. Once recorded into sequencer memory a performance can be graphically or audibly edited into a musical performance, played back and saved to any digital storage media for recall at any time.
02-What are the advantages of hardware sequencers?
Hardware sequencers are stand-alone devices designed for the sole purpose of sequencing MIDI data. The advantages of hardware sequencers are ease of use and portability. Most are designed to emulate the basic functions of tape transport (record, play, start/stop, fast forward and rewind). A moderate amount of editing features are available, including note editing, velocity, and other controller messages, program change, cut and paste and track merging capabilities.
The disadvantages of hardware sequencers are the small LCD editing display used to display programming, track and editing information.
03-What are the advantages of software sequencers?
Software sequencers are the most common type of sequencer, they run on all types of personal computer and take advantage of the hardware and software versatility that a computer can offer in the way of speed, hardware flexibility, digital signal processing, memory management and signal routing.
A software sequencer has increased graphical capabilities, standard computer cut and paste techniques, a windowed graphical environment (allowing easy manipulation), routing of MIDI to multiple ports in a system, the graphical assignment of instrument voices via program change messages, and the ability to save and recall files using standard computer memory media.
04-What is a piano roll editor?
A piano roll editor is an editing window with a piano keyboard on the left hand side, turned the right side up. The main part of a window represents the midi notes graphically, time dimension represented horizontally and pitch vertically. The note position on the keyboard determines its height on the graphical window, and the note duration is represented by the corresponding line length.
05-What is a 'drum map'?
A Drum Map is a graphical representation of the GM standard Channel 10 percussion. Each note is a separate percussion sound and a drum map makes it easier to remember which note is which instrument by replacing the keyboard with the names of the instrument that each note number will play. The MIDI data is entered as ‘hits’ rather than notes, as drum sounds need to be played as a hit rather than as a note of variable duration
06-What is usually seen in the 'arrange' window?
The ‘arrange’ window is where the tracks of a composition are organized. Tracks are stacked vertically in the arrange window, and a timeline runs from left to right. On the left of the ‘arrange’ window there is information of the track name, information on what instrument of a sound module or VST instrument this track plays along with the MIDI channel the track is assigned to.
07-What are Tempo/Meter maps?
A Tempo / Meter map contains information on the tempo of an arrangement, and any changed of tempo mid-arrangement. If a change in tempo occurs the tempo map will depict a vertical line at the time of the change and a horizontal line according to the tempo.
08-What is the purpose of quantizing?
Quantize is a type of time correction which is applied at the moment of recording (automatic quantize), or more commonly after the part has been recorded. It involves the moving of recorded musical events onto pre-defined beats according to a position-based grid. It can be thought of as imposing a grid of vertical lines across the event display which become ‘magnetic’ for the surrounding recorded notes whenever the quantize function id selected.
09-What is Groove Quantizing and how does it work?
Groove quantising is a type of quantization which involves quantize points or hitpoints which correspond to the rhythmic pulse of the material. Groove quantization can be used to manipulate timing, note duration and velocity information, and is used to give a track a more human feel.
10-Explain Note On quantizing.
Note On quantizing moves the start of the note to the nearest ‘magnetic’ grid value while leaving the end of the note untouched.
11-Explain Over Quantizing.
Over quantizing move the entire note start and end to the nearest correct notation position set by the quantize setting.
12-Explain Iterative Quantizing.
Iterative quantizing is another method of giving MIDI data a more human feel. MIDI data is moved closer to the correct notation position set by the quantize setting. Notes may be moved or may be left in place, depending on how close they were to the correct position and the settings of the iterative quantize.
13-What do quantize values such as 4,32,16T etc represent?
These values refer to the timings on a note grid towards which quantised data will be moved: 1/4, 1/32, and 1/16 triplet.
14-What is the score editor and how does it display musical information?
A Score Editor allows musical data to be entered into a computerised score in a number of manual and automated ways. Although scores can be manually entered, most music-transcription programs will accept MIDI input, allowing a part to be played directly into a score. This can be done in real time (by playing a MIDI instrument or finished sequence into the programme), in step time (entering the notes of a score one note at a time from a MIDI controller) or from an existing standard or program-specific MIDI file. The score editor displays a midi recording in the traditional score style, and the score may be printed out for musicians to work from.
15-How, and using what protocol, may a Sequencer be synchronised to a multitrack recorder?
Sequencers that include sync features will often read and write SMPTE time code, convert SMPTE to MIDI Time Code (MTC) and allow recorded time-code signals to be cleaned up when copying code from one analogue device to another. Certain types may be able to read specialised time-code formats that are used by modular digital multitrack machines (MDM), which allow ADAT or other MDM machines to be synchronised to the sequencer and instruments without the need for additional hardware.
16-If you change the tempo of the song, what will happen to (a) the MIDI parts? (b) the Audio parts?
MIDI parts will play at the set tempo, but audio parts will play at their current tempo and be out of sync.
17-How does the application Recycle allow MIDI to control Audio parts?
Recycle chops up the audio into smaller manageable parts based on tempo and hit value. These may be looped, time stretched and played on demand by MIDI data in a sequencer.
18-What is OMS?
OMS - Open Music System (formerly Opcode MIDI System) - A real-time MIDI operating system allowing communication between different MIDI programs and hardware. A sequencer could interface with a librarian program to display synthesizer patch names - rather than just numbers - in the sequencer's editing windows.
19-How does OMS simplify MIDI studio setups?
OMS allows internal virtual MIDI ports and connections to patch your devices together and allows access to the devices in a graphical way using the actual names of the devices and patches.
20-What's the difference between type 0 & 1 MIDI sequences?
Format 0 - all channels displayed as one track.
Format 1 - channels are displayed on individual tracks.
21-Why are there 'virtual' MIDI ports available (i.e. Hubis Loopback)?
Virtual MIDI ports allow virtual devices to connect together via software (i.e. Software Sequencer > VST-I). You could have two MIDI applications open and allow MIDI data to pass between the software applications via virtual ports (e.g. Re-Wire).
22-What is the 'rewire' protocol?
ReWire allows real-time streaming of digital audio into a sequencer (Cubase) from such things as software synths, drum modules, and other programmes such as Reason, and Live. The ReWired programme is a slave to the sequencers control functions. Rewire allows up to 64 channels of audio to be shared between applications that support the protocol.
23-What is the rocket networks protocol and how does it work?
The Rocket Networks Protocol was developed by Steinberg to allow musicians using their software to work on ideas and exchange projects through the Rocket Network Server (i.e. online).
24-What are step sequencers?
Step sequencers allow MIDI data to be entered manually by introducing notes, one at a time, in a time sequential manner.
25-Why are step sequencers usually more suitable for percussion & drum parts?
Drum parts are usually based around fixed note values and so a step sequencer is suitable for programming, 4 or 8 bars can be created then cut and pasted as the track requires. A step sequencer also ensures the correct timing of a drum part.
26-Why are click tracks important functions in MIDI/Audio sequencers?
Click tracks enable performance to be in time with the chosen track tempo and MIDI parts created at the tempo.
27-Why do many sequencers metronomes allow either Audio or MIDI clicks?
Simply to allow the performer to choose a sound that they are most comfortable playing along with.
28-How is MIDI data such as modulation and pan usually displayed in part editors?
Modulation and pan data is usually displayed in the arrange window at the bottom of the display. There is a display will correspond with the notes, like a bar graph with values / heights ranging from 0 to 127.
29-How many times is master clock transmitted per quarter note?
24
30-What are the functions of the master and slave in any synchronisation situation?
Master - transmits time code information (tempo, start, stop, song position).
Slave - slave receives time code from master and responds in sync with the master.
31-What timing division does SPP (song position pointers) work on?
1/6 beats.
32-What is MIDI Sync mode and what synchronisation protocols does it accept?
MIDI sync mode is a setting to sync a master to a slave. MIDI sync uses MIDI Time code, or MIDI clock. Once the slave device is set to receive time code it will follow the master device and remain in sync with it.
33-What is the primary difference between MIDI Time Code and MIDI Clock, and why is MTC more accurate?
MIDI Time Code differs from MIDI clock in that it used real-time (seconds, minutes) rather than information on tempo, beats and bars. This allows every device to be locked into the same clock. Also MIDI Time Code references song position data continuously (four per frame) to make up for any differences between master and slave. MIDI clock messages do not contain song position pointers and so are not as accurate as MIDI Time Code.
34-Define the basics of SMPTE?
SMPTE – Society of Motion Picture and Television Engineers – The standard method of interlocking audio, video and film transports. The use of SMPTE allows for the identification of an exact position on a tape or within a media program by assigning a digital address to each specified length. This address code cannot slip, always retains its original location and allows for the continuous of tape position to an accuracy of between 1/24th and 1/30th of a second. Each audio or video frame is tagged with a unique time code address, an eight digit address displayed in the form 00:00:00:00 where the successive pairs represent hours:minutes:seconds:frames.
35-What similarities are there between SMPTE and MTC?
MTC is based on SMPTE, with both using a real time 24 hour clock for synchronising devices.
36-How does FSK work?
FSK - Frequency Shift Keying - An audio tone (frequency) modulated by a square wave used both for data transfer and also for sequencer and drum machine synchronization. FSK is the sound heard from a fax or modem making as it establishes communication. Before MIDI, drum machines or sequencers were synchronized to each other or to a tape machine via this method. The only information transmitted was a rate which was interpreted as tempo by the machines. There was no location information included so the song always had to be started from the very beginning in order to achieve proper sync. If there was any drop out or glitch along the way meant that the track had to be started again from the very beginning to re-establish sync.
37-Does standard-FSK synchronisation give any indication of song position?
No, FSK can only sync if played from the beginning of a track.
38-What improvements does Smart-FSK offer over standard FSK?
Smart-FSK contains real-time song position data in the code allowing a song to be synced from any playback position.
39-If using FSK with analogue tape, why must the speed of the tape not change after recording the FSK timing information?
By increasing or decreasing tape speed, 1.5 and 2.5 kHz frequencies will change. The converter can only handle these frequencies so it may not be able to read the signals.
40-What is the 'tempo master' and what is the 'transport master' within a MIDI synchronised setup?
Tempo Master – The machine / sequencer that sets the tempo for the slaves to follow.
Transport Master - The device that performs the play, stop and continue tasks as followed by the slave devices.
41-What problems may arise from extensive use of controller data within a MIDI piece?
Control data from pitch wheel or pan movements use a high amount of MIDI bandwidth. MIDI is a serial protocol; therefore a delay in transmitted messages / latency can occur.
42-Name 2 different connection protocols for MIDI interfaces?
USB / Firewire.
43-Can tempo changes and time signature changes be made during a song within a sequencer?
Yes
44-What considerations must be made when using a software sequencer as part of a live show?
- The tempo must be followed by other performers from the start – the drummer / bass player may need a click track in headphones.
- The computer and the Operating System must be as stable as possible.
- A backup plan should be in place in case of sequencer failure – acoustic instruments, comedy sketch, etc  |
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Sat May 08, 2004 2:52 am |
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albertom
Joined: 21 Jan 2004
Posts: 22
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01-What is a MIDI sequencer?
This is computer software that records the computer information from MIDI instruments and MIDI controllers transmit. Quite literally, the computer information that makes up the music is put into order or sequenced. A MIDI sequencer is similar to a multi-track audio tape recorder in that it stores a musical performance. It even has similar controls: PLAY, RECORD, STOP &
PAUSE. However, a MIDI recorder does not record sound. It records data about each note that is played.
02-What are the advantages of hardware sequencers?
Hardware sequencers are stand-alone boxes that perform many of the same functions as their software-based counterparts. Easy to use for live performances.
03-What are the advantages of software sequencers?
The advantages of a software sequencer include: More memory, more intensive editing features, Graphical display.
04-What is a piano roll editor?
The piano roll screen displays individual notes as black lines. These lines also indicate the length and pitch of the note. By placing the cursor over the note a window displays the name of the note C2, F5 etc. By clicking on any of the notes at the top of the screen and then on one of the piano keys to the left of the screen a note of that duration will appear which can then be inserted anywhere.
This screen also allows copying and pasting of individual notes, groups of notes or entire sections of the piece.
05-What is a 'drum map'?
Is a map which shows how drums /percussion instruments are assigned to keyboard notes.
06-What is usually seen in the 'arrange' window?
It contains the tracks and parts. In this window you organize your piece of music, whether it's the whole piece or just a section.
07-What are Tempo/Meter maps?
The Tempo map provides both a graphic display of the tempo and a list of all tempo changes in your project.
08-What is the purpose of quantizing?
The Quantize command rounds the times of notes to the nearest specified time interval. This is very useful for correcting timing errors in your music. Both the start times and durations of the notes can be quantized.
09-What is Groove Quantizing and how does it work?
This command lets you specify precision in time, duration, and velocity of notes so you can synchronize tracks with each other or with a predefined pattern, the groove pattern. With a carefully defined groove pattern, you can give an old song an entirely new feel.
Groove quantization allows the user to choose from a number of styles of feels and apply one of those feels to his own sequence. The user may also use his own sequences as templates to quantize other pieces to.
10- Explain Note On quantizing.
Note On quantizing simply shifts the beginning of notes to the nearest Quantize value, keeping note lengths intact.
11-Explain Over Quantizing.
Over quantizing is quantizing the note to the point where the note on and note off are both quantized to the nearest value, and can result in losing expression from the piece.
12-Explain Iterative Quantizing.
Iterative quantizing moves the notes closer to the correct notation position set by the quantize setting.
13-What do quantize values such as 4,32,16T etc represent?
Notes value. A quarter note, a 32nd note, and a 1/16 note triplet.
14-What is the score editor and how does it display musical information?
Score editor is a type of display of MIDI data on a song. The score editor displays information in the form of standard musical notation.
15-How, and using what protocol, may a Sequencer be synchronized to a multitrack recorder?
When you require pieces of audio, video, or music technology equipment (eg. tape recorder and sequencer) to work together, you may need some means to make sure that they play in time with each other. This is called 'synchronization', which gets shortened to 'sync' or even 'synch'.
A magnetic tape-recorder track is the region of the tape that is scanned by one recording head element. It can, for example, carry an audio signal, that is an electronic analogue of a stream of sound. In order to use an audio track to record sync information, the information must be encoded into an audio-compatible signal, called a sync tone. An audio tape track on which a sync tone has been recorded is called a 'stripe'. It is desirable that the synchronized devices can join in wherever you start up the sync tone, even if it is not at the beginning of the stripe; this is called 'chasing'. The SMPTE/EBU timecode standard defines the predominant internationally accepted standard for a sync tone and it allows devices to 'chase' or locate to a precise position.
In music technology applications, with equipment which is not timecode compatible, you may be able to use a tape sync unit by way of a tempo-relative stripe system. Examples of such systems are’ traditional FSK (Frequency Shift Key) and the Philip Rees proprietary FSKplus format.
16-If you change the tempo of the song, what will happen to (a) the MIDI parts? (b) the Audio parts?
Midi parts tempo will be affected, audio tempo will remain the same.
17-How does the application Recycle allow MIDI to control Audio parts?
Designed as an adjunct utility for audio-editing and multitrack software, ReCycle pretty much does one thing: it offers better time shifting through loop slicing — and it slices loops exceedingly well. If you have a sampler, you can then load the slices
You adjust the tempo of any loop and export it as a new WAV or AIFF file. ReCycle even exports a Standard MIDI File beat map for that purpose.
Once a groove has been broken down to the component drum hits and their sequence of Note On times, you can easily adjust the tempo, quantize the performance, or replace any of the sounds.
18-What is OMS?
What is OMS?
OMS, the Opcode MIDI System, is a Macintosh system extension that bridges the gap between MIDI applications and MIDI hardware. It acts as an internal MIDI patchbay/switcher, so that any MIDI device can talk to any other through the computer.
OMS gives you access to hundreds of MIDI channels. OMS is like a palette from which you pick the devices and MIDI channels that you'll need. The MIDI interface determines the number of simultaneous MIDI channels, but OMS gives it access to every device and MIDI channel in your studio.
20-What's the difference between type 0 & 1 MIDI sequences?
MIDI files having Format 0 must store all of the MIDI sequence data on a single track. This is generally useful only for simple "single track" devices.
Format 1 files, which are the most commonly used, store data as a collection of tracks.
21-Why are there 'virtual' MIDI ports available (i.e. Hubis Loopback)?
A virtual MIDI router is a software driver that simulates any number of MIDI ports on your computer. You can transfer MIDI data between software applications that are running simultaneously on the same computer
22-What is the 'rewire' protocol?
Generally ReWire is a technology for transferring audio data between software applications, in real time, the software equivalent of a multi-channel audio cable. ReWire provides up to 64 channels of real-time audio (at extremely high resolution and practically any bandwidth) to be transferred between applications. It also ensures sample accurate synchronization between clients and server, and provides common transport functionality (play, stop, locate etc.) for the entire system.
23-What is the rocket networks protocol and how does it work?
Rocket network protocol is used when you want to work in a project with other performers via the internet. This protocol allows exchange, via rocket specific servers, of MIDI or audio files. You need to use a software that supports this protocol (usually an audio sequencer), and you need to pay for it. This protocol is good when you want to have rapid exchange, although not yet real-time, of files. It’s also nice in that it works inside the software. Still you may simply exchange files for free using the internet, although not as user friendly, it’s cheaper.
24-What are step sequencers?
Software designed primarily for making beats, rhythm tracks and drum loops "from scratch" using MIDI and/or samples. Most step sequencers use some type of grid to define the beats. Each spot in the grid represents the On/off State of a drum or instrument sound at a specific time.
25-Why are step sequencers usually more suitable for percussion & drum parts?
In order to create beats, rhythm track and drum loops.
26-Why are click tracks important functions in MIDI/Audio sequencers?
In order for musicians to synchronize their performance with each other in a multitrack environment (where a player may add a track at a different session for example) it is common practice to record a metronome signal on one of the tracks of a multitrack.
This track may also be generated electronically via computer sequencers and other devices.
Click tracks are also used in film music recording to tightly synchronize music performance to picture.
27-Why do many sequencers metronomes allow either Audio or MIDI clicks?
Most all of the sequencers sold today can combine audio tracks with MIDI tracks and play them back in perfect synchronization! This pretty much eliminates the hassles involved with synching analog tape to MIDI tracks.
28-How is MIDI data such as modulation and pan usually displayed in part editors?
As numeric values between 0 and 127.
29-How many times is master clock transmitted per quarter note?
The master sends a Clock message 24 times for every quarter note, which defines the tempo for the slaves and keeps it in sync.
30-What are the functions of the master and slave in any synchronization situation?
The master sends out special MIDI messages to tell the slaves when to start and stop playback, as well as what tempo to keep. These messages include Start, which tells the slaves to start playback from the beginning of the current sequence; Stop; Continue, which tells the slaves to start playing from the last stop point; and Song Position Pointer, which identifies any point in the sequence at which the slaves should begin playback. The master also sends a Clock message 24 times for every quarter note, which defines the tempo for the slaves and keeps it in sync.
The software sequencer can be the master or a slave; when synching MIDI devices, it doesn't matter. The master is set to Internal Clock mode, and the others are set to External Clock mode.
When synching to tape, the sequencer should be a slave, because it can easily adjust its tempo according to the speed of the tape deck. In this situation, SMPTE time code is used instead of MIDI sync.
31-What timing division does SPP (song position pointers) work on?
Song position pointers work well within music-only systems - where the tempo of the music is a common factor.
32-What is MIDI Sync mode and what synchronization protocols does it accept?
MIDI Synchronization, or MIDI Sync, is usually used to synchronize the sequencer with drum machines, stand-alone MIDI hardware sequencers, and sequencers built into MIDI keyboards.
Two protocols, MIDI Time Code (MTC) and MIDI Clock.
33-What is the primary difference between MIDI Time Code and MIDI Clock, and why is MTC more accurate?
MIDI clock signals are not simple pulses. Each clock message is a single byte. Clock messages are sent at the rate of 6 per semiquaver (a semiquaver = "sixteenth note"). A MIDI clock "beat" is the duration of one semiquaver - so there are 6 MIDI clock messages per MIDI beat.
So, a MIDI sequencer refers to a position in a sequence of events in terms of musical divisions such as b
.eats and bars. The MIDI beat does not therefore occupy a fixed amount of time. Its duration depends on the speed ("tempo") of the music.
This is in contrast with timecode where the timing information relates to "real" time (seconds, minutes, hours).
34-Define the basics of SMPTE?
SMPTE - (Society of Motion Picture Television Engineers) is timecode to lock a computer to a movie or video. This allows the user to insert sound effects or music at very precise points in movies or videos. Most movies are at 30 frames or pictures per second, and the operator could insert the sound effect on any frame or picture. You must have an additional piece of equipment hooked up to your computer to use this feature
SMPTE Longitudinal Timecode encodes its data into the rate (frequency) of electronic state transitions. The binary value 0 is represented by a single transition at the start (or 'boundary') of the bit-period (or bit 'cell'). The binary value 1 is represented by a two transitions - one at the start and the second in the middle of the bit period. This scheme is called 'Bi-Phase Mark'.
35-What similarities are there between SMPTE and MTC?
Distribution of timing information and allows a MIDI controlling device to program other MIDI ("slave") devices.
36-How does FSK work?
The simplest form of sync is known as FSK (Frequency Shift Keying), a system which records a series of electronic tones (usually 1kHz and 2kHz bursts) onto tape, at a tempo related to the tempo of the song you're working on. These tones are derived from MIDI clock, which is based on sub-divisions of the song's tempo. Many drum machines have FSK sync built in, which means that even if you don't have a sequencer, you can still sync your drum machine to tape.
Once you've sorted out your song arrangement, the starting tempo, and any subsequent tempo changes, it's simply a matter of playing back your programmed song and recording the code to tape. Because the code is tempo related, if the song speeds up, the code speeds up, so there are no conversion processes or other complexities to worry about.
Once the code is safely on tape, the output of the code track is fed back into the sync input of the drum machine (or whatever MIDI device you're using), the drum machine is set to external MIDI sync, and you're in business. Providing you start the tape before the start of the song, the drum machine will receive a MIDI start command and run in perfect sync with the tape.
37- Does standard-FSK synchronization gives any indication of song position?
No. The main disadvantage of simple FSK is that whenever you stop the tape, you have to wind back to the start again to restore sync, which can be a real pain when you're working on the end of a long song.
38-What improvements does Smart-FSK offer over standard FSK?
An enhanced version of FSK, known as Smart FSK, gets around this very neatly, providing that the sequencer or drum machine being locked up recognizes MIDI Song Position Pointers (as most modern units do). Smart FSK may be used in exactly the same way as basic FSK, the difference being that you can start the tape anywhere in the song and you'll be sync'ed and running within a second or two. Smart FSK will give you all the practical benefits of SMPTE but with fewer complications.
39-If using FSK with analogue tape, why must the speed of the tape not change after recording the FSK timing information?
Because the code is tempo related, if the song speeds up, the code speeds up, so there are no conversion processes or other complexities to worry about.
40-What is the 'tempo master' and what is the 'transport master' within a MIDI synchronized setup?
Tempo master is the machine that sets the tempo that is followed by the slave machines. Transport master is the device that performs the play, stop and continue tasks that are followed by the rest of the slave MIDI devices.
41-What problems may arise from extensive use of controller data within a MIDI piece?
Controller messages like pitch wheel or pan make intensive use of MIDI bandwidth. Because the MIDI is a serial protocol, there can be a delay in transmitted messages, not only controller messages but also all the other types of messages.
42-Name 2 different connection protocols for MIDI interfaces?
Audio drivers, plug-in formats, and MIDI-interface engines.
43-Can tempo changes and time signature changes be made during a song within a sequencer?
Yes.
44-What considerations must be made when using a software sequencer as part of a live show?
Reliability, consistency. Is it easy to manage??
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Thu May 20, 2004 12:51 am |
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