Two-time Grammy winner Cissy Houston, the 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 family at her New Jersey home while being treated in hospice for Alzheimer’s disease, ABC News reported.

“Our hearts are filled with pain and sorrow. We lose the matriarch of our family,” daughter-in-law Pat Houston said in a statement, adding that her Houston contributions to popular music and culture are “unparalleled.”

“Mother Cissy has been a strong and prominent figure in our lives. A woman of deep faith and conviction, who cared deeply about family, ministry and community,” said Pat. “Her career in music and entertainment spanning more than seven decades will remain at the forefront of our hearts.”

As a member of the vocal group Sweet Inspirations, Houston sang backup for Otis Redding, Lou Rawls, The Drifters and Dionne Warwick, alongside Doris Troy and Dee Dee Warrick. They also sang backup for Elvis Presley, Aretha Franklin and sometimes Houston sang side by side with her daughter Whitney.

As a session singer, Houston 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.