How many angels can dance on the head of a pin?

This is an old, old question debated for centuries by countless theologians and students of philosophy (see Thomas Aquinas). Part of the problem is determining how large or small an angel might be, and what sort of dance is to be performed. Obviously a dance such as the Jitterbug would require more room than say a waltz. However, in reality, angels do not Jitterbug.

Assuming the dance is no more than a mere Foxtrot, the correct answer is 23.