Also, get rid of the canvas's ability to display different shapes on the same canvas, since we never use that feature anyway.
Pattern muteing/unmuteing (via GUI or MIDI) takes effect the next time the pattern loops.
Notes 1-128 on Channel 1 correspond to patterns. NOTE ON triggers the pattern at the given moment, a second NOTE ON stops it at a given moment. NOTE OFF does nothing. Also, patterns triggered via the GUI are no longer forced to be in lock-step.