I haven't tried this, but I was thinking about it. I think if you wanted great quality, you'd either have to have a high end video recorder, or possibly record your music separately via any recording s/w then dub it over the video you record. Just like the real thing :)

I'm just guessing. It's possible you can get decent video cameras that can take a midi input or something directly as you record. I'm really not sure what's out there.

Have you tried asking someone who's video you've watched?