I've uploaded a new developer version. This has a number of minor bug fixes and is certified to work with python3 (or your money back!).
The big new feature is an ARTICULATE for plectrum tracks. This makes it easy to get a "jazz like" guitar sound.
Get it at
http://mellowood.ca/mma/downloads.html#developerAnd PLEASE LET ME KNOW ABOUT ANY BUGS! My plan is to release a full distribution later this month.