Keeping order effortlessly

One year, at my high school's talent show, a band of students performed "Don't Change" by INXS.  Some audience members were so into the performance that they jumped on stage and started dancing.  Our principal, as though he'd seen this many times, walked calmly onto the stage and simply shook his head at each dancer.  In a testament to his ability to keep order, every dancer improvised a quick skip down the stairs and off the stage, as though their exit had been planned.  With just a simple head shake, the principal was able to clear the stage of dancers.  That's what being principal--and nearly 6 1/2 feet tall--gets you.