We all know that it's not just good singing that sets the good a cappella groups apart from the great ones. Nor is it the adventurous choice of songs or the exciting arrangements. No, the key final step is some fine choreography.
Here are a couple collegiate a cappella groups to illustrate. First, the UC-Berkeley Men's Octet performing "Bohemian Rhapsody."
And now, the BYU Vocal Point doing a version of "Thriller" with zombie lurches and headsnaps that I guarantee will make you smile. Particularly the one about 1:09 of the way in.