What Do You Call What These People Are Doing In This Video?

Friday evening at Agave restaurant on Bertrand, the band busted into "Rockin' Robin" by the Jackson 5.  Just then, several people, busted into something else.

As the band played the fun cheerful little ditty from the Jackson 5, a few patrons this particular evening, started to do, or tried to do, this hand jive thing you probably last saw someone do in 6th grade.  What is that called?