ben m
Joined: 15 Sep 2002
Posts: 337
Location: UK |
| Week 10 - Applications of Music Technology |
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Ok,
here are the questions for the last topic(!)
Even though there aren't loads this week, you will find that some of the questions will require a little extra research.
Good luck everyone.
If during the recording of a MIDI part the musician has problems accurately performing a simultaneous note/pitch bend, how may this be solved?
If a PC or MAC is used in a life performance with a sequencer, what would be more useful, lower latency settings or larger disk buffer settings?
How long (in seconds) would 1 bar of music at 100BPM last?
If a delay unit with no tap/tempo sync options is to be used, what is the relationship between the delay time in ms and the tempo of the track in bpm?
How would the above setup be used to create an eigth-note delay in a 120BPM track?
How would the above setup be used to create a quarter-note delay in a 80BPM track?
How woud a click track typically be used and routed in a live setup?
How could an electric guitar be used to create MIDI information?
What is digital amp modelling?
If digital amp modelling is used with no cabinet emulation, what will be the effect on the sound?
How could a digital amp modeller be used live with amp switching controlled by a sequencer?
How can digital amp/cab modellers be used live to reduce onstage sound levels?
When using loops that have been triggered from a sampler via MIDI, what implications does it have on the engineers choice of playback position?
When using true analogue hardware synths on tour, what issues may there be with tuning?
Why may it be useful to record a live performance onto multitrack rather than a stereo medium?
What is punching-in/out and how is it useful in studios with limited tracks?
Briefly explain how MIDI can be used to control the lighting and visual elements of a show including how MIDI information is converted.
How could a pitch-bend wheel be used to control lights in a 'xmas light' style in a live situation?
What problems are there with using MIDI for lighting control?
What is the MSC protocol?
Why should MSC not be used to control equipment such as pyrotechnics?
What do the MSC commands Go, Stop and Fire usually do?
How accurate in the time domain is MSC?
What 3 parts are there to a MTC command?
What is a Macro in MSC terms?
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ben@audiocourses.com |
Tue May 11, 2004 6:03 pm |
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hoggs33
Joined: 09 Feb 2004
Posts: 55
Location: Nottingham, England |
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Here are my last lot of answers!!!!!
Couldn’t get my head round the delay timing questions for some reason this week. Perhaps we could go over them on Sunday. 
If during the recording of a MIDI part the musician has problems accurately performing a simultaneous note/pitch bend, how may this be solved?
The note and pitch bend could be recorded separately by overdubbing.
If a PC or MAC is used in a life performance with a sequencer, what would be more useful, lower latency settings or larger disk buffer settings?
If it is anything like my machine a fine balance between the two to get the best possible sound. Lower latency would be preferable however to avoid any timing problems on playback.
How long (in seconds) would 1 bar of music at 100BPM last?
Here is how I worked this out:-
Assuming a 4/4 time signature there would be 4 beats in a bar. If a bar was 60 bpm divide 60 beats by 60 seconds giving an answer of 1 so there would be 1 beat every second therefore the bar would last 4 seconds.
For 100 BPM divide 60 by 100 giving 0.6 beats per second. Multiply this by the 4 beats and therefore the bar would last 2.4 seconds.
However for some reason when I try this out in Sonar it gives a time of 2.12 seconds so now I am confused!
If a delay unit with no tap/tempo sync options is to be used, what is the relationship between the delay time in ms and the tempo of the track in bpm?
There would be 60,000 ms per beat
How would the above setup be used to create an eigth-note delay in a 120BPM track?
How would the above setup be used to create a quarter-note delay in a 80BPM track?
How woud a click track typically be used and routed in a live setup?
The click track would be generated by a sequencer or even pre recorded and sent to whichever performer wanted to hear it via foldback on a headphone so that it was not heard by the audience.
How could an electric guitar be used to create MIDI information?
I am aware that software and hardware is available that would convert the signal from a guitar into MIDI information. A device such as the KT drum trigger could be used also I guess so that the transients of a recorded guitar part could be used to trigger a midi track or create a new midi track.
What is digital amp modelling?
This can be software or hardware that simulates different amplifiers and speaker cabinets and is generally used when recording guitars or bass directly into a DAW or other type of recorder and eliminates the need to have separate amplifiers which would need mic’ing up.
If digital amp modelling is used with no cabinet emulation, what will be the effect on the sound?
This would produce a brighter cleaner sound by removing any distortion or warmth.
How could a digital amp modeller be used live with amp switching controlled by a sequencer?
The amp modeller could be controlled by MIDI messages from the sequencer. Most hardware and software amp modellers have midi connections to enable this.
How can digital amp/cab modellers be used live to reduce onstage sound levels?
They eliminate the need for a stack of amps which themselves would create a certain amount of buzz as well which would also be picked up from any mics used to mic the amps. As the instruments are plugged straight into a desk and the PA it should give a cleaner sound.
When using loops that have been triggered from a sampler via MIDI, what implications does it have on the engineers choice of playback position?
It is likely that playback would have to start from the beginning of the track in order for the samples to be triggered correctly to be in sync with the rest of the track.
When using true analogue hardware synths on tour, what issues may there be with tuning?
The tuning could be affected by temperature chanes in different venues and by heat during the actual performance.
Why may it be useful to record a live performance onto multitrack rather than a stereo medium?
This would give more flexibility for mixing the performance for release at a later date without having to worry about getting the mix right during the performance. It would also give more flexibility for editing in the future and for overdubbing any dodgy parts that may have been played during the performance.
What is punching-in/out and how is it useful in studios with limited tracks?
Punching in and out is basically re-recording or adding a small section of a song to improve on what has already been recorded or to try out different ideas. A section of the track will be set for where the recording will start and finish and only this section will be recorded while the remaining tracks are being played back.
With limited tracks punch ins can be ‘stacked’ on top of each other and recalled later to get the best performance rather than trying out different recordings all on separate tracks.
Briefly explain how MIDI can be used to control the lighting and visual elements of a show including how MIDI information is converted.
Midi messages can now be sent to many different devices that are not just confined too music. If a midi sequencer is used it could send on and off messages to the lighting as well as other messages that may control how light or dark the light shines similar to using velocity messages for sounds. I assume some sort of converter box ( a midi controlled lighting unit) would be needed as an interface between the sequencer and the lighting control . By controlling the lights like this it makes it somewhat easier for them to be in time with the music and many more lights could be controlled in this way than by doing everything by hand.
How could a pitch-bend wheel be used to control lights in a 'xmas light' style in a live situation?
The pitch bend control would have to be assigned to the lights and then depending on the position of the bend wheel this would light up certain lights as it moves.
What problems are there with using MIDI for lighting control?
Most commercial units only use the MIDI Note- on messages to extract the light channel and intensity values. Also by using this Note on strategy, it prevents the midi port from being used to drive other sound modules etc. I guess programming is likely to be fairly complex and time consuming.
What is the MSC protocol?
MSC is Midi Show Control which is a protocol that is an extended version of the original MIDI. In addition to a ‘go’ command, cue numbers and other information can be transmitted.
Why should MSC not be used to control equipment such as pyrotechnics?
I would assume that due to the possible hazards associated with using pyrotechnics, they should not be under any sort of automation and need full ‘human’ control.
What do the MSC commands Go, Stop and Fire usually do?
Go – light on or starts a command
Stop – light off or stops a command
Fire – performs a pre-programmed function such as flashing light.
How accurate in the time domain is MSC?
Very accurate – similar to the accuracy of MIDI time code.
What 3 parts are there to a MTC command?
A status byte followed by 2 data bytes.
What is a Macro in MSC terms?
A sequence of pre-programmed lighting instructions carried out as one command. It is defined by a 7 bit number programmed to the control device. |
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Sat May 15, 2004 4:43 pm |
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griff505
Joined: 23 Feb 2004
Posts: 68
Location: Bristol |
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1. If during the recording of a MIDI part the musician has problems accurately performing a simultaneous note/pitch bend, how may this be solved?
The pitch bend and the notes can both be corrected in the sequencers MIDI Editor once the recording process is complete.
2. If a PC or MAC is used in a live performance with a sequencer, what would be more useful, lower latency settings or larger disk buffer settings?
Lower latency would be the most important feature – to keep in time with other players / the PA system. The disk buffer setting should also be optimised as much as possible to optimise stability.
3. How long (in seconds) would 1 bar of music at 100BPM last?
If the piece’s time signature is 4/4 then it would last 2.4 seconds. ((60 / 100) X 4)
4. If a delay unit with no tap/tempo sync options is to be used, what is the relationship between the delay time in ms and the tempo of the track in bpm?
60,000 / BPM = ms per beat – for quarter beat delays (divide by 2 for eights, 3 for eight-note triplets, or 4 for sixteenths.
5. How would the above setup be used to create an eight-note delay in a 120BPM track?
60,000 / 120 = 500 / 2 = 250ms
6. How would the above setup be used to create a quarter-note delay in an 80BPM track?
60,000 / 80 = 750ms
7. How would a click track typically be used and routed in a live setup?
The click track should be sent to a the person requiring it via headphone foldback, or lights which show the current tempo. The click track needs to be kept out of the main mix, or any mix going to the PA. Usually it would be the drummer who plays along with the click track, although I have seen a Bjork live performance where an orchestra plays along to ‘tempo lights’ which keep them in time with Mark Bell from LFO who was sequencing the beats live.
8. How could an electric guitar be used to create MIDI information?
Using a guitar pickup which converts the vibrations of the string into MIDI information, such a pickup is made by Roland. Alternatively software can be used which coverts audio into MIDI note on and off messages.
9. What is digital amp modelling?
Digital amp modelling uses digital processing / computer algorithms to generate the sound of specific amplifiers / cabinets. It is used often in combination with guitar or bass and a DI box. It allows the player to get a desired sound without having to own a certain cabinet, amplifier or microphone.
10. If digital amp modelling is used with no cabinet emulation, what will be the effect on the sound?
The sound of the cabinet and microphone emulation will be lost and only the amplifier will be simulated. This will result in a sound richer in bass, and lacking high frequencies – the drive and warmth with be lost from the sound.
11. How could a digital amp modeller be used live with amp switching controlled by a sequencer?
Most modelers are MIDI capable - they can be controlled by incoming MIDI messages. A sequencer could be programmed to send messages instructing the modeler to switch presets, increase gain, etc.
12. How can digital amp/cab modellers be used live to reduce onstage sound levels?
There would be no need for an amplifier or speaker cabinet onstage. The bass / guitar player would plug directly into the amp/cab modeler which would be plugged directly into the live mixing board. This would result in less noise due to the DI process, as opposed to microphones positioned to record amplified speaker cabinets.
13. When using loops that have been triggered from a sampler via MIDI, what implications does it have on the engineers’ choice of playback position?
Playback should start at the beginning of the track in order for the loops and samples to be in sync with the rest of the track / other players.
Also playback should be started before the first loop is triggered in order for the first loop to sound.
14. When using true analogue hardware synths on tour, what issues may there be with tuning?
Analogue synths are sensitive to changes in temperature. The intonation / tuning of the synth will change along with temperature.
15. Why may it be useful to record a live performance onto multitrack rather than a stereo medium?
Recording to multitrack would allow mixing to take place at a later stage. You can apply different processing on different instruments. Or, would it be necessary and affordable, whole additional tracks with new instruments / vocals could be added in studio.
16. What is punching-in/out and how is it useful in studios with limited tracks?
Punching-in/out is a function of a multitrack which allows the user to mark the exact position from where recording should start (punch-in) and where it should stop (punch-out). When record and play are pressed, the recorder starts and ends at these positions automatically.
This is a useful technique for correcting mistakes in a take when track count is limited – no extra / spar track is required.
17. Briefly explain how MIDI can be used to control the lighting and visual elements of a show including how MIDI information is converted.
MIDI is control data; it is not limited to music applications. MIDI-to-Analog interfaces can be used to control many electrical devices via MIDI. A sequencer could send out Note On / Note Off messages, with note number indicating which light is to be controlled and the velocity information determining how bright or dark the light should be. Alternatively Program Change messages could be used to switch between lighting presets.
18. How could a pitch-bend wheel be used to control lights in a 'xmas light' style in a live situation?
The MIDI converter can accept Pitch Bend Change messages which contain information about pitch bend value. The value could be made to correspond to the number of light to be switched on, or the speed at which the lights flash on / off (with 0 being constantly on).
19. What problems are there with using MIDI for lighting control?
Limited functionality: – Commercial control products often offer just Note On with velocity, or just the ability to switch between presets.
- The note-on method prevents the MIDI port being used to drive other sound modules etc. as notes will sound.
- Writing sequences with Note On style is difficult.
20. What is the MSC protocol?
MIDI Show Control - A protocol for controlling a multitude of equipment during live shows. MIDI Show Control allows MIDI systems to communicate with and to control dedicated intelligent control equipment in theatrical, live performance, multi-media, audio-visual and similar environments. Also MSN is used to control certain musical tools whose functions aren't normally covered by standard MIDI messages. For example, MIDI Show Control can be used to control a digital tape recorder, accessing various features over MIDI such as setting the punch-in and punch-out times for an overdub.
21. Why should MSC not be used to control equipment such as pyrotechnics?
Because of the risks physical risks involved in pyrotechnics they should be controlled by a human, MSC should not be used in case it malfunctioned or needed to be aborted or changed during a show.
22. What do the MSC commands Go, Stop and Fire usually do?
Go - Starts a transition or fade to a cue. Transition time is determined by the cue in the Controlled Device. If no Cue Number is specified, the next cue in numerical sequence GO-es. If a Cue Number is specified, that cue GO-es. Transitions "run" until complete. If the Controller wishes to define the transition time, TIMED_GO should be sent.
Stop - Halts currently running transition(s). If no Cue Number is specified, all running transitions STOP. If a Cue Number is specified, only that single, specific transition STOPs, leaving all others unchanged.
Fire - triggers a preprogrammed keyboard Macro.
23. How accurate in the time domain is MSC?
MSC time code and user bit specifications are entirely consistent with the formats used by MIDI Time Code and MIDI Cueing and are identical to the Standard Time Code format proposed in MIDI Machine Control 0.05. Some extra flags have been added, but are defined as such that if used in the MIDI Time Code/Cueing environment they would always be reset to zero, and so are completely transparent.
MSC subframe data is represented in fractional frames measured in 1/100 frame units, as specified by MIDI Cueing specification.
24. What 3 parts are there to a MTC command?
A status byte (describes the action, such as “Note On,” and includes the channel the command is addressing) followed by two data bytes (the first data byte tells MIDI what note to play, while the second data byte tells MIDI how loud to play the note).
25. What is a Macro in MSC terms?
Macro is a programmed sequence of commands. Macro is defined by a 7 bit number and programmed at the Controlled Device or loaded via MIDI file dump facilities. |
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Sat May 15, 2004 9:14 pm |
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iNSTiNCT2765
Joined: 05 Nov 2003
Posts: 60
Location: Denmark |
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Week 10 – Applications of Music Technology
If during the recording of a MIDI part the musician has problems accurately performing a simultaneous note/pitch bend, how may this be solved?
The musician can do this in two steps. Record the notes in first and then after that, record the pitch bend on the same MIDI channel.
If a PC or MAC is used in a live performance with a sequencer, what would be more useful, lower latency settings or larger disk buffer settings?
A good balance between latency and buffer size is preferable but a noticeable latency will make the sequencer play with a delay and it won’t sound good. I think it’s better, in a live performance to have the music play in sync with a low latency and have a few sporadic clicks and pops due to a small buffer size rather than having a noticeable delay.
How long (in seconds) would 1 bar of music at 100BPM last?
60/100 * 4 beats = 2.4 seconds
If a delay unit with no tap/tempo sync options is to be used, what is the relationship between the delay time in ms and the tempo of the track in bpm?
60000 milliseconds per minute / bpm gives a quarter-note delay. Then to get other note pulses, you can multiply or divide.
How would the above setup be used to create an eighth-note delay in a 120BPM track?
60000 ms/ 120 bpm = 500 ms (quarter-note)
Divide this by two to get an eight-note delay giving 500 ms/2 = 250 ms.
How would the above setup be used to create a quarter-note delay in an 80BPM track?
60000 ms/ 80 bpm = 750 ms
How would a click track typically be used and routed in a live setup?
The click track can be generated by the MIDI sequencer that is used in the live setup and is fed to the performers through a foldback system so it isn’t audible to the audience. The click track is like the ‘timecode’ for each of the musicians to help them play in sync.
How could an electric guitar be used to create MIDI information?
A guitar can be hooked up to a MIDI converter like the Shadow SH 075. It works by converting the analogue vibrations of the strings into electrical signals and performing digital pitch analysis. The pitch is determined by measuring the time of one sinus vibration. This information is then sent to the MIDI sequencer as a standard MIDI message.
What is digital amp modelling?
A digital amp modeller simulates a variety of cabinets and amplifiers for guitars and basses digitally. The bass or guitar can be plugged directly into this box and recorded, which eliminates the need for miking up a cabinet. Digital amp modelling also comes in a software form like the IK Multimedia Amplitude to change the characteristics and sound of already recorded guitars and basses.
If digital amp modelling is used with no cabinet emulation, what will be the effect on the sound?
The sound will be bright and clear as the effect removes the warmth and distortion from the original.
How could a digital amp modeller be used live with amp switching controlled by a sequencer?
By using MIDI messages, the sequencer can switch between amp models within the digital modeller for different songs so the musician doesn’t have to switch guitars or amps.
How can digital amp/cab modellers be used live to reduce onstage sound levels?
There will be no cabinets or amps present on stage since the guitar or bass can be directly plugged into the digital amp modeller using DI. This eliminates the buzzing and humming sounds the cabinets can produce.
When using loops that have been triggered from a sampler via MIDI, what implications does it have on the engineers choice of playback position?
The choice of playback position is made less flexible because the loops are only heard if you start playing at their triggering position (the beginning of the loop). It is not possible to start playback in the middle of the loop and have the loop play from there.
When using true analogue hardware synths on tour, what issues may there be with tuning?
The tuning of the synths can change due to the temperature. So the hardware synth may start playing out of tune if being used for a long time or in different venues.
Why may it be useful to record a live performance onto multitrack rather than a stereo medium?
Recording a live performance onto multitrack instead of a stereo medium gives you more flexible editing capabilities later on. You have more mixing freedom and the possibility of adding effects or further EQ’ing to individual tracks.
What is punching-in/out and how is it useful in studios with limited tracks?
Punching-in/out is the process of recording a small section of new material overtop of already recorded material. This is done, for example, if a vocal phrase needs to be rerecorded but the rest of the vocal is ok. This is useful in studios with limited tracks because you don’t need to record the new phrase to a separate track but right on top of the same track. This of course erases the previously recorded material.
Briefly explain how MIDI can be used to control the lighting and visual elements of a show including how MIDI information is converted.
MIDI messages can be sent to non-musical equipment such as lighting units. The messages can determine when the lights are turned on and off and the brightness of the lights can be set using the velocity settings of MIDI messages. The MIDI messages are probably sent to a converter unit first and then changed into electrical signals and then sent to the units if they don’t accept MIDI messages directly.
How could a pitch-bend wheel be used to control lights in a 'xmas light' style in a live situation?
If each light is assigned to a separate note then by bending the pitch over a lot of notes can give a moving light effect.
What problems are there with using MIDI for lighting control?
The MIDI port used for lighting won’t be able to be used for other devices because of the Note On method.
What is the MSC protocol?
MSC is MIDI Show Control and allows MIDI systems to communicate with and control dedicated control equipment in theatrical and live performances and similar setups. MSC is used to control such things as smoke, lasers, strobe lights, lighting fades/flashes, video monitors, animation etc.
Why should MSC not be used to control equipment such as pyrotechnics?
They should not solely be controlled by MSC but there should also be the human control due to the dangers of pyrotechnics. MSC can be very precise but the system needs to be monitored constantly by somebody to make sure nothing goes wrong.
What do the MSC commands Go, Stop and Fire usually do?
Go – starts a transition
Stop – stops a transition
Fire – triggers a pre-programmed macro.
How accurate in the time domain is MSC?
MSC timing is similar to MTC.
What 3 parts are there to a MTC (MSC?) command?
A MIDI Show Control message consists of:
A device ID to determine what device is receiving the command.
The command such as GO, STOP, FIRE.
Data such as a cue list, cue number or a console macro number.
What is a Macro in MSC terms?
A macro is a pre-programmed sequence of commands that are loaded via MIDI-dump or at the control device. A macro is defined by a 7-bit number. |
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Sun May 16, 2004 10:38 pm |
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