Over at AudioJungle, we're running a composition challenge. To enter, you take our motif in either MIDI or MP3 format, and incorporate it into your own composition - but the motif must remain the main theme of the track.

The reward for your labors? The winning contestant gets a brand new Mbox 2 Pro, which is valued at US$799 and comes with Pro Tools LE. It's everything you need to make music at home.

If you haven't already got an AudioJungle account, head over now and grab one. AudioJungle is a marketplace for musicians, where you can sell your loops, songs, samples, sound effects and other audio to buyers around the world.

If you want to find out more about the composition challenge - and the prize that goes along with it - you should check out this blog entry with all the details and instructions.