What a cool tool!!!
"Like to Write Music?
Most folks never get a chance to answer this question, since writing music takes years of experience... if you don't play an instrument or spend lots of time around music, you'll probably never get to write a song.
MySong automatically chooses chords to accompany a vocal melody, allowing a user with no musical training to rapidly create accompanied music. MySong is a creative tool for folks who like to sing but would never get a chance to experiment with creating real original music. Come on, you know who you are... you sing in the car, or in the shower, or you go to karaoke clubs, or you just once in a while find yourself singing along with catchy commercial jingles. MySong is also a great tool for songwriters who want to quickly experiment with melodies and accompaniments." from http://research.microsoft.com/~dan/mysong/