Quoted in The Big Beat: Conversations with Rock's Greatest Drummers ↑

A jailbird breaking rocks

The choreographer said, “We need a musical thing to go with the dancing.” They wanted to be able to visualize a jailbird breaking rocks. I came up with those [opening snare drum] shots. Me and Scotty started playing it and it worked.

D. J. Fontana, as quoted in The Big Beat: Conversations with Rock’s Greatest Drummers