Abundant Music - Generate royalty free music with a simple but very powerful procedural music creator
Captain Chords - Write chord progressions in your favorite DAW
AthTek DigiBand - AthTek DigiBand is a piece of automatic music composition software for Windows.
RapidComposer - MusicDevelopments RapidComposer: Music Prototyping and Automated Composition Software
WolframTones - Listen to what I just found in the WolframTones music universe
Band-in-a-Box - Band-in-a-Box is so easy to use!