Two-time Grammy winner Cissy Houston, mother of pop icon Whitney Houston and a powerful singer in her own right, has died at the age of 91, her family said.

Houston died Monday surrounded by her family at her home in New Jersey while receiving hospice care for her Alzheimer's disease, ABC News reported.

“Our hearts are full of pain and sadness. We are losing the matriarch of our family,” daughter-in-law Pat Houston said in a statement, adding that Houston’s contributions to popular music and culture were “unparalleled.”

“Mother Cissy was a strong and prominent figure in our lives. “A woman of deep faith and conviction who cared deeply about family, service and community,” said Pat. “Her career spanning more than seven decades in the music and entertainment industry will continue to be close to our hearts.”

As a member of the vocal group Sweet Inspirations, Houston sang alongside Doris Troy and Dee Dee Warrick as backup for Otis Redding, Lou Rawls, The Drifters and Dionne Warwick. They also sang as replacements for Elvis Presley, Aretha Franklin and, at times, for Houston, alongside their daughter Whitney.

As a session singer, Houston has recorded more than 600 songs across various musical genres and her voice can be heard on songs with Beyoncé, Chaka Khan, Donny Hathaway, Jimi Hendrix, Luther Vandross, Paul Simon, Roberta Flack and her daughter.