source file: m1508.txt
Date: Wed, 19 Aug 1998 00:46:25 +0100

Subject: tuning on synths

From: neuwirth  <neuwirth@smc.univie.ac.at>

in answer to david griffel searching for a program
for tuning synths for realtime performances.

there are 2 ways of doing it.

yamaha and roland synths both have sysex messages for
scale tuning, which allows you to change the tuning of all
tones in one pitch class (all c's, all c#'s ..)
in increments of 1 cent.
the sysex messages are vendor specific and therefore different.

general midi has master channel tune in increments of
100/8192 cents (much finer)
so it is possible to tune each channel separately.
if you play all c's on channel 1, all c#'s on channel 2,
you can use this to play in alternative tunings,
and the technique will work for every fully
general midi compliant synthsizer (roland and yamaha both 
will work).

since a midi keyboard (or any other midi instrument)
will produce notes only on one channel, you need a tool for 
rechannelizing.
there is a freeware program 
midicable
which allows you to do exactly that.

so with any decent patch editor speaking general midi
and midicable you can use the channel fine tune method
to create alterntive tunings.

i will have a presentation at the annual meeting of the
mathematical societies of the united states in january
in san antonio where i will use this technique
to explain the mathematics behind different historical tunings.

the title will be

eine kleine mathematische nachtmusik

--
Erich Neuwirth <neuwirth@smc.univie.ac.at>
Computer Supported Didactics Working Group, Univ. Vienna
Visit our SunSITE at http://sunsite.univie.ac.at