(Video Link)
Actually, it's not the real Darth Vader. It's just an actor dressed up as Darth Vader. Specifically, this is Jonathan Arons, who puts on a truly original performance for people at a senior center in New York City.
via blastr | Aron's Website
I was thinking the same thing. Maybe not the ideal target audience for this. Interesting combination of themes, though, and extra points for playing trombone wearing a full helmet!