And then there's Mozart, for string quartet and two French horns: "Ein Musikalischer Spass," A Musical Joke.

This is actually a multi-layered, complicated thing. As I recall it has four movements, and you need some twenty minutes of time to get through it.

The wrong notes written in are obvious, and so are some of the rhythmic mistakes, also written in. All to depict incompetent players. But Mozart also gets some things out of his system about incompetent COMPOSERS, who write things that he cannot bear to hear performed -- so of course Mozart has his hapless sextet executing some groaners, but they are bad jokes on the COMPOSER's level. People who sit through a performance, and giggle at the big WHOOPEE funny spots, can barely appreciate how much rehearsal Mozart requires to execute all the gaffes...correctly. I do hope Mozart felt better after getting that off his chest.