Re: Quarter-tone MIDI

[Juergen Reuter]

On Wed, 29 Oct 2003, Morteza Dehghani wrote:

> It appears to me that quarter-tone notes are not converted to the right
> frequency in the midi format of the file. Is there a patch for this, if
> not which source file needs to be modified in order to fix the
> frequencies?
> Thank you,
> Morteza
>

MIDI generally does not support quarter-tones, since pitch encoding in
MIDI is based on a chromatic scale rather than on frequency (that's one
of the reasons why MIDI is called a "musical" interface rather than an
"audio" interface).  Of course, their are "workarounds" possible such as
using the pitchbend controller or the instrument tuning request command to
fine-tune some of the chromatic scale pitches to become quarter-tone
pitches; but all these solutions have severe drawbacks.  E.g., the
pitchbend workaround will effectivele reduce the number of available MIDI
channels similar to the tuning request command, which is available only on
some MIDI devices.  If you are interested in more details about this, I
recommend to have a look at the MIDI specification.

Greetings,
Juergen