pitch bend event

[LagodViads]

It seems Pitch Bend was not implemented.

The following patch implements this by adding a new class :

PitchBendEvent

Using field "bend", containing a float ranging [-1,1], zero meaning no bend.

addPitchBendpatch.txt

[Garrett Grimm]

Hi @LagodViads,

Thanks very much for implementing this, I've merged it into master via PR #66.

-Garrett