As part of the British Invasion of the 1960s, the Who rank with the Beatles and Rolling Stones as one of the most influential bands of the 1960s, starting with the early hit "My Generation."
The British-born Entwistle teamed up with Daltrey in 1960 while working as a tax clerk. Four years later, the Who was born.
With legendary performances at the Monterey Pop Festival in 1967 and subsequently at Woodstock, the Who cemented its legend. They may have been the first act to regularly destroy their instruments as part of the show — a practice many musical bad boys, including members of Nirvana, have emulated. The band broke new creative ground with the first rock opera, Tommy.
At the House of Blues in West Hollywood Thursday, another giant of 1960s rock — Doors keyboardist Ray Manzarek — learned of the news while announcing that the three surviving members of the group would reunite for the first time since 1971 to headline the "Harley-Davidson Open Road Tour."
"Could we have a moment of silence for one of the great, great rock 'n' roll bass players of all time, a real genius," Manzarek said. "That guy was was amazing … wasn't he? Dressed like a spider, he came on stage. He was just incredible."
Manzarek recalled when the Doors and the Who played together at the Isle of Wright Festival in 1969. "We played, then the Who came out and did the public debut of Tommy. Entwistle was just the strongest bass player I've ever seen … a gentleman and a really quiet cat."
Over the years, the band sold 18 million albums, according to the Recording Industry Association of America. They have had 14 gold albums, 10 platinum and five multiplatinum.
They retired in 1982, but reunited and toured frequently. They gave a rousing performance at last year's "Concert for New York," which raised money for the victims of the Sept. 11 attacks. ABC Radio's Al Manzini in Las Vegas contributed to this report.