🚀 go-pugleaf

  Here's what I'm doing for dynamically tuning a keyboard in just intonation.
I'm using MAX and a K2000. I had tried using poly key pressure as a pitch
modulator, however I had problems with chirping as the note quickly adjusted
from equal to just tuning. Even though the poly key message was sent 
immediately follwing the note on, the K2000 took a while to adjust. The
K2000 as well as other synths don't recognize a poly key pressure if there
is no note playing at that pitch, so you can't send the pressure message
before the note on. What I use now which works great, but probably isn't
possible on other synths is to send a MIDI channel controller immediately
before the note on and use the sample and hold feature of the K2000's 
function generators to sample the controller's value and hold it for the
duration of that note. This allows me to have polyphonic just tuning on
a single MIDI channel. 
  The software I have written in MAX can function in several ways. Keyboard
retunings can happen by pressing keys on my old Mirage keyboard, which is
only used as a panel of MIDI buttons. Or, one channel from my sequencer
can be routed to MAX and call up retunings using note on's. This allows
me to sequence a track of tunings which I can play within later. Tunings
can also be set using the algorithmic generating program I have written
in MAX.
  Retunings can affect all the keys, only the white, only the black, or
the even or odd whole tone scales. I have a big library of 12,7,6,and 5
note tunings which can be transposed and assigned to any of these key sets.
  In my own work I have been using a 72 equal note per octave tuning, 
however I meet each week with Ellen Fullman who has built an instrument
of 108 longitudinally vibrating strings over 80 feet long which are excited
by rosin coated fingers and is tuned to a set of 42 just pitches. In fact,
I'm leaving for the warehouse right now. Later...
   --- james mccartney