Estelle Bennett, a former member of the singing trio the Ronettes, has died at the age of 67.
The group, best known for their 1963 hit Be My Baby, epitomised the 'wall of sound' production technique pioneered by Phil Spector.
Bennett was found dead at her apartment in Englewood, New Jersey on Wednesday, said her brother-in-law Jonathan Greenfield.
The cause of Bennett's death has not yet been determined.Greenfield, the manager and husband of the Ronettes' lead singer Ronnie Spector, said his wife was devastated.
"Estelle was Ronnie's sidekick," he said.
"[Estelle] was very much into fashion and worked with Ronnie on the whole look and style of the Ronettes."
The Ronettes were inducted into the Rock And Roll Hall Of Fame in 2007, billed as "the premier act of the girl group era".
"They could sing all their way right through a wall of sound," the Rolling Stones' Keith Richards said at the induction ceremony.
"They didn't need anything. They touched my heart right there and then and they touch it still."
Ronnie Spector, Estelle Bennett and their cousin Nedra Salley signed with Phil Spector's Philles Records in 1963, having hits with Walkin' in the Rain, Baby I Love You and Sleigh Ride.
Bennett is survived by a daughter, Toyin Hunter, and three grandsons.