Bobby Womack, a legendary soul singer-songwriter-guitarist whose songs were covered by the Rolling Stones and the J. Geils Band, has died at the age of 70. Although the cause of death has not yet been revealed, he had recently received treatment for colon cancer.

The news was broken by Rolling Stone, noting that his label, XL Recordings, confirmed Womack's death. Womack is the second soul great to pass away this week. On Sunday, Mabon "Teenie" Hodges, a member of the Hi Records house band and co-writer of several of Al Green's biggest hits, died of emphysema.

Born in Cleveland in 1944, Womack learned how to play guitar at a young age and formed a gospel group with his four brothers. They were discovered in 1956 by Sam Cooke, who signed them to his SAR label a few years later and changed their name to the Valentinos to move them in a secular direction. They only had had two hit singles, but they were heard by the right people. Their first, 1962's 'Looking for a Love,' became the first hit for the J. Geils Band in 1971, but it was their second that became their most famous.

The Rolling Stones heard the Valentinos' 'It's All Over Now' through WINS' famous DJ Murray the K on their first U.S. visit. A week later, they cut their own version while at Chicago's Chess Studios. The song became the Stones' first No. 1 in the U. K.

The Valentinos broke up after Cooke was killed, but Womack continued on. He became a session guitarist in Memphis, contributing to records by Joe Tex, the Box Tops and Aretha Franklin. By 1968, he released his first solo album, 'Fly Me to the Moon,' a mixture of standards, pop covers and his own compositions which set the template for a series of popular albums in the 70s. The exception was 1972's 'Across 110th Street,' which was the soundtrack to a blaxploitation film.

Another song of his, 'Trust Me,' was covered by Janis Joplin on her posthumous album, 'Pearl.' In his autobiography, 'I'm a Midnight Mover,' after cutting the song 'Mercedes Benz' -- which was inspired by Womack's car -- he wrote, "I took her back to her hotel room, she got a phone call. She only spent a couple of minutes chatting and then put the phone down. She told me a guy was going to swing by. Her drug connection and he wanted me out. She told me I had to go. We hugged and I left. I wasn't in my bed more than a few hours when someone called up to tell me Janis was dead, that she had OD'd. I was shocked, I was one of the last people to see her alive."

Womack had his own problems with drugs, entering rehab in the '80s for cocaine addiction, but continued to record regularly through the '90s. He was elected to the Rock and Roll Hall of Fame in 2009. In 2012, he released his first album in more than a decade, 'The Bravest Man in the Universe,' which received near-unanimous critical praise. He had been working on a new album, 'The Best is Yet to Come,' at the time of his death. The record will have guest appearances by Stevie Wonder and Rod Stewart.

Hear the Valentinos' 'It's All Over Now'

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