This is incredibly creative and well done. I love the tight "synth" and "brass" harmonies. The one track that bugged me whenever it was there, though, was track #50, "muted guitar". It wasn't quite in tune and was of a different quality than the other tracks. Maybe you could try some alternative recordings of it? It would be quick since it is a one measure loop. Just a suggestion... :-)
I would love to hear you do other songs. You remind me of the Swingle Singers. You can hear an excerpt of the James Bond theme at http://www.swinglesingers.com/audio/bond.html.