yeah, I can't find the full clip from the newest film version(my fav one) on youtube anymore, think they took it down.
It's from a musical called The Producers. It's a Mel Brooks film about a broadway producer and his accountant who team up to try and show the worst play they can find in hopes that it will flop and they can gain money from it. They end up doing a play called  "Springtime for Hitler" which was written by an used-to-be Nazi.

It's a really funny movie, one of my favorites. If you like that sort of super politically incorrect stuff, ((Mel Brooks stuff >.> )) I would highly suggest trying to find it and check it out.
Can't find the actual clip, but these are the three songs that make up the scene "Springtime for Hitler"

www.youtube.com/watch?v=uG6G1D…
www.youtube.com/watch?v=oLPfaE…
www.youtube.com/watch?v=IiuxjQ…

I know this all by heart and have shamelessly sang it hundreds of times.