source file: m1341.txt
Date: Mon, 2 Mar 1998 08:53:56 -0600 (CST)

Subject: Re: Identification of pitches

From: mr88cet@texas.net (Gary Morrison)

>I am developing software to automatically implement alternate tunings in
>MIDI files through the use of pitch bends or other methods.

   Sounds like a great project!  Good luck with it.

   There has been a lot of talk in the past on this list about using
pitch-bend for implementing unusual tunings.  Perhaps now would be a good
time for all of us WHO HAVE ACTUALLY TRIED IT (I haven't) to update us on
your experiences with it.  Be sure to include notes on relevant aspects of
your music (e.g., how many timbres you're attempting to play at a time,
whether real slurs are common in the resulting music, how fast your notes
are playing, and probably other factors).

   The problems that have been cited include that it's impossible to send
the pitch-bend message and the note-on simultaneously, and that the MIDI
1.0 spec itself does not specifically state how much a given amount of
pitch-bend deflection should affect the pitch of the note.  There were
other considerations mentioned too, I think.  (The simultaneity concern
regards the possibility of there being a "blurp" in either the attack of
the new note, or the release of the previous note in cases where the two
notes are completely legato or slurred).

   Solutions proposed include accepting a single timbre, and allocating a
single channel for each of the nominal 12 pitches, or allocating channels
in pairs, and alternating notes between them, and sending pitch bend
messages before the next note begins playing, while the note on the other
channel is playing.  (All that combined obviously with not playing more
than one pitch at a time on a given channel.)