This is intended as a desktop version of my browser music analysis tool, allowing for more complex setups and level of control. (Also because a statically-typed language makes all the difference...)
I'm planning support for the functional harmony analysis track, multiple instrument tracks and sound synthesis modules, and fine (visual!) control over note volume, pitch-bend, or any other arbitrary parameter.
Effectively, this would become a full-fledged music tracker, with an emphasis on things I care most.