Emperor: 'If I were a rich man' from Fiddler on the Roof.
Suho1004: This is actually a question that has intrigued scientists and artists alike for ages, and not one that (I believe) has an easy answer. It is generally agreed that classical music as a genre is very difficult to reproduce through rythmic buttocks slapping (RBS). Many people favor show tunes (like our good Emperor, for example), primarily because they are catchy and memorable, but this does not always equal ease of reproduction. One opinion that has gained currency recently in RBS circles is that folk songs or children's songs may be the genre(s) that will ultimately yield the Holy Grail of RBS. Post-modern RBS experts eschew the idea of genre altogether, and followers of a certain saxophone-playing former U.S. president (who was also an RBS enthusiast) often ask what is meant by the term "buttocks."
No definitive conclusions have been reached yet, so it safe to say that the question is still open to interpretation.