I was playing around with Isle of Tune (links play music, sort of):

• Here is Come As You Are (uh, more or less; I have all kinds of work to do with the chorus to make it right)
• Also here is something random I composed

Give ’em a thumbs up, won’t you?  That is, if they meet your rigorous standards for quality of music made by little cars driving past musical landmarks.  Or thumbs down if that’s how you feel.  It’s anonymous and I can take it.

This is a lot of fun to play with, but time consuming.  You also can’t exactly make a song like you want it, there is a very definite set of notes and effects and you’re constrained to three tracks that need to loop appropriately to keep things going.