Ah, very cool - I do this too actually, I use
Sonic Producer for making my beats and it's pretty friggin cool!
Here's a video that I recorded of it in action -
Sonic Producer Video ReviewI recorded this video with
Replay Video Capture.
If you want the music ONLY and not the audio, you could always extract the MP3/audio file using
Replay ConverterSorry for all the links, just so much good stuff here!
Media Guru