Apparently, this guy can't play guitar. Instead, he videotapes himself playing notes and edits them together to make a video of himself playing Motzart. Over 1000 cuts. 6 hours of guitar tabbing. 1 hour of shooting. God knows how much editing.
FLIGHT OF THE CONCHORDS
I'm pretty sure these are real, but not for the US market. If you like this, check out the out-takes on YouTube.