Cow Palace, 1973: The Who's Keith Moon Passes Out From Drugs, And An Audience Member Fills In

Drummer Keith Moon (1947 - 1978) of English rock group The Who, 24th April 1973. (Photo by Michael Putland/Getty Images)

November 20, 1973 was an unforgettable night for drummer Scot Halpin: Keith Moon of The Who passed out on stage, and Halpin stepped out of the crowd to take his place. What could have been more surreal and enticing for a fan than the sight of Roger Daltrey, Pete Townshend, and John Entwistle of The Who conferring upon you the sacred duty of maintaining the beat in the absence of their regular (and legendary) drummer? That night at the Cow Palace in Daly City, California, the first show of The Who's "Quadrophenia" tour, is one Halpin would never forget -- and as a rock-fan claim to fame, it's one of the coolest ones on record.