Music theory 101: A 4/4 beat means there are four beats to a bar. There are different ways of emphasizing the beats within a bar: on the 1 and 3, the 2 and 4, and the off-beat (between beats; think what ska sounds like).
Most popular music is in 4/4 time. The simplest rhythm–the so called “four-on-the-floor” beat–features the bass drum on the 1 and 3 with the snare hitting on the 2 and 4. Because we’re dealing with even numbers, it’s the easiest beat for dancing.
This guy, however, says that one particular 4/4 rhythm–one where the emphasis is on the 2 and 4–“short circuits the moral frontal lobe.” Christians beware!
Send in the asteroid. We’re done on this planet. (Via Tom)