LMMS/lmms — pull request #769 by diizy (2014-05-25 11:11:09+00:00)
Title: InstrumentTrack: skip processing entirely if the track is muted - a way ...

...to conserve CPU power: notes won't be played at all on a muted track. If the user wants the notes to be processed without making a sound, the only use case for that is using a peak controller, and that has its own mute button anyway, so there's really no reason to process notes on a muted track, that I can think of.