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JovianPyx
Joined: Nov 20, 2007 Posts: 1988 Location: West Red Spot, Jupiter
Audio files: 224
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Posted: Fri Feb 19, 2010 1:26 pm Post subject:
Microtonal Music with Standard MIDI Equipment |
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Some may know me here as an FPGA synth guy. And in fact, I design MIDI synthesizers using FPGAs as a hobby.
I own a nice MIDI keyboard controller - Korg Wavestation - which has pitchbend wheel, mod wheel, joystick and velocity keyboard with channel aftertouch.
I would like to do microtonal music with this keyboard (because I can't afford a different or new one) and my own microtonal synthesizer in an FPGA. The ability to get other than the standard 12 note western music scale is simply a matter of a tuning table (in my FPGA world).
My question is how does one deal with scales that are more than 12 notes per octave, like 24 ET or 72 ET or others?
I do a lot of MIDI sequencing from a PC (Cakewalk), and because I can design my synthesizer, I can make it respond any way I wish to messages from the sequencer.
I can think of several ways to accomplish this - but what do others do? _________________ FPGA, dsPIC and Fatman Synth Stuff
Time flies like a banana. Fruit flies when you're having fun. BTW, Do these genes make my ass look fat? corruptio optimi pessima
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kkissinger
Joined: Mar 28, 2006 Posts: 1356 Location: Kansas City, Mo USA
Audio files: 42
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Posted: Fri Feb 19, 2010 1:44 pm Post subject:
Re: Microtonal Music with Standard MIDI Equipment |
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JovianPyx wrote: | How does one deal with scales that are more than 12 notes per octave, like 24 ET or 72 ET or others?
I do a lot of MIDI sequencing from a PC (Cakewalk), and because I can design my synthesizer, I can make it respond any way I wish to messages from the sequencer. |
Here are a few possibilities:
1) Use program change events to switch between patches that are detuned
For example, Program 1 could be your patch, Program two would be the exact same patch except that it is transposed up -- say by 50 cents. In multi-timbral mode, you would simply send note messages to either the shifted or non-shifted patch.
2) Use velocity to control pitch
Set up your patch so that the pitch varies with the velocity. For example, less than 64 would give you unison pitch and greater-than or equal 64 gives you a shifted pitch. You could set up a range if you wanted, too. The advantage of this is that you only tie up one channel and that, since velocity data is note-unique, you can mix tuned and de-tuned pitches on a polyphonic channel. (This was somewhat successful on my VZ1 synthesizer.)
Sequencers tend to be biased in favor of 12TET however if you take an "tempered pitch + offset" approach, then that might be a little easier than a "1/2 step becomes 1/4 step" approach.
However, if you use a piano roll editor and ignore the note names, then you could simply track at any interval without getting hung up on the actual note names. _________________ -- Kevin
http://kevinkissinger.com |
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JovianPyx
Joined: Nov 20, 2007 Posts: 1988 Location: West Red Spot, Jupiter
Audio files: 224
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Posted: Fri Feb 19, 2010 2:01 pm Post subject:
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Thanks Kevin,
Sorta what I thought.
I do use piano roll and even with 12ET music, I ignore the note names
I also thought I could do the bits that conform to 12TET in piano roll (standard way) and then insert messages on another MIDI channel to get the "other ones" such as for 24ET, the second MIDI channel would be a 12ET tuned 1/4 tone up or down. This could be handled in one synthesizer that responds to both MIDI channels. I realize that this would cause problems with running status... I could use other normally unused continuous controller messages to force the tuning differently for the next new events until zero message is received (which turns that off). Using velocity is another solution but also has it's own problems - but I don't think I will use velocity because I'm not that fluid a keyboard player anyway, I do most of my composition manually in piano roll mode with an editor.
You've at least confirmed the notion that there isn't going to be an easy, musically sensible, convenient way to do this and that I just need to work at it (which I had assumed at the start). _________________ FPGA, dsPIC and Fatman Synth Stuff
Time flies like a banana. Fruit flies when you're having fun. BTW, Do these genes make my ass look fat? corruptio optimi pessima
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