While watching the Grammy awards last Sunday, it occurred to me that American culture has been defined by music ever since the end of World War II. After the Germans and Japanese surrendered in 1945, millions of GIs returned home to marry and begin families. The big-band era of good-time music accompanied that, and romantic singers like Frank Sinatra ruled the day.

In the ’50s, many young people, tired of conformity, began to rebel. The rise of Elvis Presley illuminated that rebellion. Then the angst kind of died out as Chubby Checker ushered in “The Twist” in 1960, and Americans began dancing all over the place.

Exhausted from doing “The Pony,” young consumers eventually began to respond to the snappy melodies of an English group called The Beatles, and once again, music mania gripped the nation. The British invasion featured the four mop-tops, The Rolling Stones and The Animals, among others.