This guy deserves huge ammounts of praise. He has singled handedly midified the Mahavishnu SongBook. This book had until recently been out of print since 1976. It was republished in February 2007.Details here.
I have one simple midi track, with several layers. How to combine all the notes into one single layer? If I select all regions, then right click context menu -> Selected Regions-> Edit-> the Combine option is greyed out. That would seem the right idea, but maybe that is for audio tracks only. 2b1af7f3a8