PGMusic has come up with lots of cool utilities through the years. Here's one I'd like to see:

1) utility program should be able to load a song in mp3 format or play from a CD

2) all program commands should be voice activated with simple one-syllable commands like
PLAY, STOP, BACK, NEXT, SET, LOOP, CUT

3) then, when you want to learn a difficult passage from a CD, you could run the utility program, put on a headset (the kind with a mic), and without ever taking your hands off the instrument SET markers in the song that can be LOOPed through until you can repeat the passage... then CUT the marker and SET a new one

this would be useful not only for practicing musicians who often need to learn challenging songs for gigs in very short time frames... it would also be useful for music teachers and music students

THe visual interface wouldn't have to be anything but a dialog box to pick the song, and maybe make some setup changes for the mic. But If you want to make it REALLY intriguing, set up a visual that graphically compares the original song to what the performer is playing... or add some kind of grading system "you hit ... 70%... of the notes accurately..."