KANSAS CITY (Reuters) — Niki Sullivan, who played rhythm guitar and sang backup for Buddy Holly on his early hits with The Crickets, has died.

Sullivan, 66, died Tuesday in his sleep at his home near Kansas City, according to Tricia Earl of The Buddy Holly Center in Lubbock, Tex.

At an appearance two years ago at the museum, Earl said, Sullivan recalled the uniqueness of Holly’s early music when The Crickets recorded such enduring rock and roll hits as “That’ll Be The Day” and “Maybe Baby,” on which Sullivan’s voice can be heard in the original version.

Sullivan toured with The Crickets through 1957 but left the band when it became apparent Holly did not need a second guitarist, Earl said.

Sullivan also had his own musical aspirations, forming The Plainsmen and The Hollyhawks, but met with little success.

A few months after Sullivan left The Crickets, the band broke up and Holly struck out on his own. The small plane he chartered after an Iowa concert crashed on Feb. 3, 1959, killing the 22-year-old Holly and fellow rockers Ritchie Valens and J.P. “The Big Bopper” Richardson. The event was immortalized as “The Day the Music Died” in Don McLean’s hit, “American Pie.