You're probably not going to crank out any concert-worthy concertos using KissTunes, but you can have a bit of fun with the simple computer-as-musical-keyboard model it uses to generate user-created songs.
KissTunes turns the home row and a few secondary keys above the home row, into a keyboard-like tool for composing simple tunes. You can edit your work, share it and even back up the tunes you create to your computer. Check out the video below, which covers just about everything you can do with KissTunes:
Craving a more advanced virtual-jam session? Check out previously reviewed JamStudio for a multi-instrument virtual music maker.