Soul icon Isaac Hayes dies at 65

US singer-songwriter Isaac Hayes has died at his home in Memphis, Tennessee, at the age of 65. Police were called after his wife found him unconscious next to a moving treadmill. He was taken to hospital, where he was pronounced dead. Hayes, a flamboyant, deep-voiced performer, won an Oscar for the 1971 hit Theme From Shaft. He was perhaps better known to a younger audience as the voice of Chef from the hit cartoon show, South Park. The cause of death was not immediately known.

"Family members believe at this point it is a medical condition that might have led to his death," a police spokesman said, adding Hayes was being treated for "a number of medical issues". Hayes suffered a stroke in 2006. But he was about to begin work on a new album for Stax, the soul record label he helped build to legendary status.

British soul star Jazzie B, who became friends with Hayes after they performed together in the 1990s, described him as "a really nice man" and "as cool as ice. He was an equal cornerstone to the evolution of hip-hop, what's come to be known as R&B, and urban music in general," he told BBC News. "So there's absolutely no doubt that Isaac Hayes will be truly missed and he was a very influential part of music as we hear it today."

Collin Stanback from the Stax label told the Associated Press news agency that the star "embodies everything that's soul music". He added: "When you think of soul music, you think of Isaac Hayes - the expression, the sound and the creativity that goes along with it."

The showman

Hayes - along with Al Green, James Brown and Stevie Wonder - was one of the dominant black artists of the early 1970s. The star, a self-taught musician, was hired in 1964 by Stax Records as a pianist and saxophonist, working as a session musician for big names such as Otis Redding.

He established a songwriting partnership with David Porter, and in the 1960s, writing hits for Sam and Dave such as Hold On, I'm Coming and Soul Man. This success led to a recording contract, and in 1969 he shot to fame with the release of the groundbreaking album Hot Buttered Soul. The theme from the film Shaft was a number one hit in 1971. He won an Academy Award for the song and was nominated for another one for the score. The song and score also won him two Grammys.

In a statement released from The Recording Academy, the body behind the Grammys, president Neil Portnow called him a "true renaissance man". He added: "After laying the groundwork for the Memphis soul sound through his work with Stax Records, his groundbreaking theme song and score for the movie Shaft cemented his status as a musical icon. The world has lost a true creative genius and a passionate humanitarian, but his indelible legacy will remain ever present. Our deepest sympathies go out to his family, friends and all who were inspired by the man and his music," added Mr Portnow.

When he was elected to the Rock and Roll Hall of Fame in 2002, he put his success down to good chance. "I knew nothing about the business, or trends and things like that," he said. "I think it was a matter of timing. I didn't know what was unfolding."

Hayes was also in several movies, including It Could Happen to You with Nicolas Cage, and Ninth Street with Martin Sheen. He achieved a different of popularity later in life as the voice of the South Park character, Chef. But he angrily quit the show in 2006 after an episode mocked Scientology, a religious movement to which he belonged. He was married four times and has 12 children.