Initialize the mixer for playing this track
volume formula used:
volume = (trackVolume + volumeSlide + volumeTune) *
envelopeVolume * fadeoutVolume
panning formula used:
p = panning + effects.panningSlide
panning = p + min(p,1-p) * (envelopePanning - 0.5) * 2
the rate is calculated in a format specific way using:
note + fineTune + relativeNote + noteTune + noteSlide