Harmony and microtonality with OASYS

sirCombatWombat · Post by **sirCombatWombat** » Mon Mar 03, 2008 11:46 am

I am studying harmony and microtonality in music, and I found few software products that can alter the tuning on synths realtime. One even reacting real time on the notes the user is playing.

The "insurmountable" tuning problem called the "Pythagorean comma" has been solved! The Justonic Tuning Cube can retune an electronic music synthesizer in real time, allowing pure harmony to be maintained in every chord.

http://www.justonic.com/homepage.html

I want this! And I have searched the manuals and have not found any indication that OASYS would support this!

The software above does not have a demo version so that I could try this on my OASYS.
I found that at least Kurzweil, E-mu, Yamaha, Ensoniq, Roland and Native Instruments have products that support this tuning via SysEx.
I am not saying this to bash Korg, but to convey that it is viable.
I'm not certain but I think this is the mechanism, http://www.midi.org/about-midi/tuning.shtml

I have used OASYS's User Tunings for my studies, and I think it is flexible enough to support real time tuning with SysEx. At least it can alter the tuning in realtime manually.
Please understand that I don't want this only for my studies, I see vast possibilities for my music in the harmonic and microtonal realm!
For example string and wind instrumentalists do this all the time, it is an essential part of their trade.

jg:: · Post by **jg::** » Wed Mar 05, 2008 6:42 am

Very interesting.

I've never tried this product, but I'm interested in anything that makes it easy to change tuning quickly.

jg::

sirCombatWombat · Post by **sirCombatWombat** » Wed Mar 05, 2008 1:04 pm

Does anyone have an idea if this would be possible with the OASYS?
I'm so much hoping that I have missed something.

sirCombatWombat · Post by **sirCombatWombat** » Mon Mar 10, 2008 10:38 am

Is there a way to download the OASYS MIDI Implementation, the manual suggests the following.

Note: To obtain a copy of the “MIDI Implementation”
which includes MIDI System Exclusive format
information, please contact your Korg distributor.

But my distributor is in another country.

I'm serious about getting the realtime tuning to work. If it simply can't be done with the current software, I request that Korg consider implementing it.

sirCombatWombat · Post by **sirCombatWombat** » Tue Mar 11, 2008 6:04 pm

Uh, this is becoming a monologue.

Well I'm progressing. I noticed that changing the user scales sends SysEx so I captured and analyzed some. I can now manually write SysEx that change any of the user scales.
There are still questions unanswered, for example I'm worried that +-99 cents is not enough for some scales. And I don't know if the tuning is fast enough for realtime playing.
But I'll check in to this some more and contact the developer of the Justonic next.

sirCombatWombat · Post by **sirCombatWombat** » Tue Mar 11, 2008 10:13 pm

I just reread my original message and noticed that I should have used the term 'user scale' instead of 'tuning', I hope I'm not confusing anyone.

sirCombatWombat · Post by **sirCombatWombat** » Wed Mar 19, 2008 5:09 pm

I tested tuning the scales in rapid succession, and it works quite fast.
Only the whole User All Note Scale from C-1 to G9 took a little longer, but that's 128 notes!

I made a document from the user scale SysEx structure and sent it to Justonic Inc.
They replied that they will implement OASYS support to the next version of Pitch Palette, and will notify me when it is ready.
I will of course write here when they do.

sirCombatWombat · Post by **sirCombatWombat** » Wed Mar 19, 2008 5:18 pm

And here's the technical stuff if somebody is interested.

-- from the manual --
The OASYS’s system exclusive message format is [F0,
42, 3n, 70, ff, …. F7]
F0: exclusive status
42: Korg ID
3n: [n=0–F] global MIDI channel 1–16
70: Future model ID
ff: function ID (type of message)
:
:
F7: end of exclusive
-- end quote --

OASYS has two kinds of user scales, one all note scale and sixteen octave scales.
Octave scale repeats for each octave, and all note scale ranges from C -1 to G 9.
Tunable range for single key is -99 to 99 cents.

Here are the messages I have acquired:

User All Note Scale
C4
00 cents
SYSX: F0 42 30 70 43 0F 00 00 27 3C 00 00 00 F7
01 cents
SYSX: F0 42 30 70 43 0F 00 00 27 3C 00 00 01 F7
99 cents
SYSX: F0 42 30 70 43 0F 00 00 27 3C 00 00 63 F7
-01 cents
SYSX: F0 42 30 70 43 0F 00 00 27 3C 7F 7F 7F F7
-99 cents
SYSX: F0 42 30 70 43 0F 00 00 27 3C 7F 7F 1D F7

G9
00 cents
SYSX: F0 42 30 70 43 0F 00 00 27 7F 00 00 00 F7

C-1
00 cents
SYSX: F0 42 30 70 43 0F 00 00 27 00 00 00 00 F7

User Octave Scale 00
C
00 cents
SYSX: F0 42 30 70 43 0F 00 00 26 00 00 00 00 F7

B
00 cents
SYSX: F0 42 30 70 43 0F 00 00 26 0B 00 00 00 F7

User Octave Scale 15
C
00 cents
SYSX: F0 42 30 70 43 0F 00 0F 26 00 00 00 00 F7

So I gather the following
First three bytes 43 0F 00 mean change user scale tuning.
Fourth byte is User Octave Scale number from 00 to 0F
Fifth byte is 27 for All Note Scale and 26 for Octave Scale
Sixth byte is Note Number, All Note Scale range from 00 to 7F and Octave Scale range from 00 to 0B
Seventh to ninth bytes are 00 00 00 to 00 00 63 for positive and from 7F 7F 7F to 7F 7F 1D for negative tuning values.
The last byte is End of Exclusive

Daz · Post by **Daz** » Wed Mar 19, 2008 6:12 pm

Thanks for digging into this Sir !

sirCombatWombat · Post by **sirCombatWombat** » Wed Mar 19, 2008 10:17 pm

Well, wombats are probably the worlds most stubborn animal.

jg:: · Post by **jg::** » Wed Mar 19, 2008 10:56 pm

Do you have one, as a pet, perhaps?

jg::

sirCombatWombat · Post by **sirCombatWombat** » Thu Mar 20, 2008 5:30 pm

Oh I would love to, but it is a protected species.