Bobby Womack, legendary singer and songwriter, influencer and collaborator, has passed away at the age of 70, his last label home XL Recordings (via Rolling Stone) has confirmed. The cause of death has not yet been revealed, though Womack was diagnosed Alzheimer's disease last year and had previously battled cancer. Womack, who got his start singing lead in a gospel group comprised of his brothers, the Valentinos, and then as Sam Cooke's backing guitarist. In the seven or so decades that followed, he wrote "It's All Over Now" for the Rolling Stones, played in sessions for Aretha Franklin and Elvis Presley, and collaborated with everyone from Rick Ross to Damon Albarn, Adele to Lana Del Rey. Most recently, he was at work on a followup to his 2012's comeback album The Bravest Man In The Universe that was set to feature Stevie Wonder, Rod Stewart and Snoop Dogg. In 2009, when he was inducted into the Rock and Roll Hall of Fame, he said: "This is just about as exciting to me as being able to see Barack Obama become the first black President of the United States of America! It proves that, if you're blessed to be able to wait on what's important to you, a lot of things will change in life."