Actually, the thing about dancing all night is precisely about drugs! First of all, you need to understand that the concept of rhythm derived from one source, common to all humanity - the heart. If a beat is slower the heart (at rest) it will be slow and relaxing. If faster than the heartbeat, it will appear to be exciting. Now, when a person dances for a long time, the body releases endorphins into the brain - these are the natural painkillers and give a feeling of euphoria. Indeed, anthropologists believe that one of the key factors in human beings developing religion was that a primitive tribes associated music with their most important rituals - those designed to create a cohesion within the community. The resulting euphoria was thus seen as an experience generated by the function (rather than the biological reason of it being the dancing that was responsible) of the ceremony - hence religion. One of the odd things about dancing is that the taller you are, the slower the music you will enjoy. This is because the human body has an arc through which it likes to oscillate to a beat. The taller you are, the larger the arc becomes and hence slower music is preferred!