MIDI-File Pitch Bend

It seems like I should have gleened this information by now, but I can't seem to
remember the answer:

As I recall, although MIDI itself doesn't specify how much pitch change a pitch
bend of, say +3 produces, general MIDI
(or something) defines a standard so-and-so number of cents pitch change per
pitch-bend increment. Questions:

#What is that amount?
#If I were to put MIDI files that make that assumption onto a web page, can
I pretty much count on it being
rendered consistently on most everybody's machine?

On Friday, Gary Morrison asked:

> As I recall, although MIDI itself doesn't specify how much pitch change a pitch
> bend of, say +3 produces, general MIDI
> (or something) defines a standard so-and-so number of cents pitch change per
> pitch-bend increment. Questions:
>
> #What is that amount?
> #If I were to put MIDI files that make that assumption onto a web page, can
> I pretty much count on it being
> rendered consistently on most everybody's machine?

No one seems to have taken a stab at this yet. Forgive me if this is redundant; my ISP had trouble
with my account over the weekend.

The General MIDI standard default setting for pitch bend is +/-1 equal tempered whole step of pitch
variation, or about +/-200 cents, depending on the resolution of the particular engine. Since the
MIDI pitch bend scale apparently has 14-bit resolution, equal to 16,384 increments, you've got a
range of -8191 to +8192 to work with. Dividing 8192 by 200 cents we get 40.96 increments per
cent. Even though very few synths offer that degree of actual pitch resolution, it does seem to be
safe to use that figure to calculate the amount of pitch bend in MIDI files for playback on GM
synths. That should get you as close to the mark as each particular instrument is capable of
being, mostly within 1 cent.

--
David J. Finnamore
Nashville, TN, USA
http://members.xoom.com/dfinn.1
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