Here's a live performance at the Isle of Wight Festival 1970 (with a bonus but unChristmasy track "The Acid Queen"). Please try not to be overwhelmed by Roger's fringe, Pete's extraordinarily high-waisted pants, and Keith's insane drumming.
See that bassist to the left? I just learned his name is John Entwistle. He's apparently incredibly mellow.
Note: I could have used a scene from the film version of Tommy, but I promised quality. Also, the combination of Ann-"overwhelming vibrato" Margret, Oliver "tone deaf but still cast in musicals" Reed, and the glassy eyed stare of a small child gives me the creeps.