Tuesday marks Bob Dylan's 70th birthday, and he's just one of a number of musical greats — including Joan Baez,  Brian Wilson, Paul McCartney, Aretha Franklin, Carole King, and Lou Reed — who recently celebrated or will soon celebrate their big 7-0. That's no coincidence, says David Hajdu in The New York Times. They all would have turned 14 — a "magic age for the development of musical tastes," according to psychologists — in 1955 or 1956, "when rock 'n' roll was first erupting" and Elvis Presley was putting out his early records. The importance of age 14 isn't limited to Dylan and his cohort. Throughout modern music history, from Irving Berlin to Billy Joel, this pattern has been evident. Here, an excerpt:

When Robert Zimmerman (the future Bob Dylan) turned 14 as a freshman at Hibbing High School in Minnesota, Elvis Presley was releasing his early records, including Mystery Train, and Mr. Dylan discovered a way to channel his gestating creativity and ambition. "When I first heard Elvis's voice I just knew that I wasn't going to work for anybody, and nobody was going to be my boss," Mr. Dylan once said. "Hearing him for the first time was like busting out of jail." ...

I can’t help wondering what a 14-year-old with Mr. Dylan’s gifts and hungers would have done if he had been born three or four years earlier and had hit his teens when pop music was in its pre-rock lull, anesthetized by the over-sugared tunes of Teresa Brewer and Vic Damone. Back then, the drive-ins raged with cool pulp-movie delinquents, like Marlon Brando in The Wild One. Would Mr. Dylan, a movie nut in childhood, have gone into screen acting to channel his rebellious spirit?

Read the entire article in The New York Times.