Elvis Presley's (search) "That's All Right" played simultaneously on radio stations around the world Monday to mark the 50th anniversary of the rock 'n roll icon's first professional record.

Scotty Moore, Presley's first guitarist, hit a button on a control board at Sun Studio (search) to begin the satellite broadcast to 1,200 to 1,500 stations.

Outside the small studio where Presley cut the record on July 5, 1954, a street party was under way, with bands performing on a sound stage at Sun's front door. More than 2,000 participants turned out by early afternoon.

"That's All Right" (search) now enjoys a prominent place in the history of American music, but it wasn't an immediate hit.

"A lot of people think it was an overnight success, but we paid our dues for two years on the road in Mississippi, Arkansas, Tennessee, Texas before RCA picked us up," Moore said.

Music historians regard the recording of "That's All Right" as a milestone in American pop culture.

"Elvis would be the first to say he didn't create rock 'n' roll. Rock 'n' roll came from an evolutionary process going back probably to the 1940s," said Kevin Kane, director of the Memphis tourism bureau.

"But there was a defining moment that took place on July 5th, and we just figured this is as good a time as any to celebrate it."

Isaac Hayes (search), who recorded for Memphis' Stax Records in the 1960s and 1970s, and singer Justin Timberlake, a Memphis native, joined Moore for the ceremony.

"He brought a lot of cultures together," Hayes said of Presley. "He brought a lot of music together."