Niki Sullivan, who played rhythm guitar and sang backup for Buddy Holly on his early hits with the Crickets, died Tuesday (April 6) in his sleep at his home near Kansas City, according to Tricia Earl

Niki Sullivan, who played rhythm guitar and sang backup for Buddy Holly on his early hits with the Crickets, died Tuesday (April 6) in his sleep at his home near Kansas City, according to Tricia Earl of The Buddy Holly Center in Lubbock, Texas. Sullivan was 66.

Sullivan played on such early Crickets recordings as "That'll Be the Day" and "Maybe Baby." He toured with the band through 1957 but left when it became apparent Holly did not need a second guitarist.

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

A few months after Sullivan left the Crickets, the band broke up and Holly struck out on his own. On Feb. 3, 1959, the small plane he chartered after an Iowa concert crashed, 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."

--Reuters