I've researched SCORING and found very little information about software and the process, so I found a solution that works for me and thought I'd share.
Sonar 8, has the ability to watch video and play live via your MIDI keyboard while recording, you can then edit and add more layers to your score if you like. I've used Fruity Loops for a while now and Sonar 8 has a lot of simularities but is far more advanced.
This video is scored using sonar 8 and I don't play piano (I think it's passable for a score):
[ame="http://vimeo.com/3362816"]"Waterfall" on Vimeo[/ame]
tell me what you think !