Isaac Hayes, soul legend and voice of Chef, dies at 65

Isaac Hayes, the pioneering musician and songwriter whose orchestral soul albums took the genre in a new direction and who became known to another generation as the voice of South Park's Chef, has died at the age of 65.

The performer, one of the most powerful and successful black musicians of the early Seventies, was found collapsed next to a running machine at his home near Memphis, Tennessee, yesterday afternoon.

With his shaved head and an outlandish dress sense, in sunglasses and draped in gold jewellery, Hayes became a soul music icon with his debut album, Hot Buttered Soul in 1969. His biggest hit, "The Theme From Shaft" – with its insistent cymbals and wah-wah guitars – came two years later, won an Oscar and a Grammy and laid the foundations for disco later in the decade.

But for years before he emerged as a star in his own right, Hayes had been one of the driving forces behind the success of the Stax record label, joining forces with lyricist Dave Porter to pen hits for the likes of Otis Reading and most notably Sam and Dave, for whom they wrote "Soul Man" and "Hold On! I'm A Comin".

Marc Willis, head of the Soulsville Foundation, which operates the Stax Museum of American Soul Music, said last night: "Isaac was unique and an inspiration to us all. His accomplishments as a musician are unparalleled."

"He was a real powerhouse in music," said Don Cornelius, the founder of the Soul Train TV series. "He took black music to another level, made it more classic."

Hayes was born on 20 August, 1942, in a tin shack in Covington, Tennessee, and was raised by his grandparents after being orphaned. He began singing at his local church at the age of five and taught himself to play piano and saxophone, joining Memphis-based Stax as a session musician in 1963. In all, Hayes won three Grammy awards, the last for the title track to his 1971 album Black Moses, which spawned a nickname that stayed with the star. He was inducted into the Rock and Roll Hall of Fame in 2002.

The star was found unconscious by his wife, Adjowa, who he met in Ghana after having been named king of a region there. He first visited the royal family there in 1992 and returned repeatedly to do charity work. The couple had one son, Nano Kwadjo – Hayes's 12th child. The marriage was his fourth.

"Family members believe at this point it is a medical condition that might have led to his death," a police spokesman said, adding that Mr Hayes was being treated for "a number of medical issues". The star had a stroke in 2006, but despite sometimes noticeably shaky interview and concert performances since then, he continued to act and to tour right up to his death.

He found an unexpected second wave of popularity in later life as the voice of South Park's resident love god, Chef, and a song in character, "Chocolate Salty Balls", became a Christmas number one in the UK.

But his time on the show ended in acrimony after 11 years in 2006, when he quit saying the writers had gone too far in their now-notorious episode lampooning the Church of Scientology, to which Hayes belonged.

In his own statement, Hayes made no specific mention of the episode, in which one of the South Park fourth-graders is mistaken for the second coming of L Ron Hubbard, the religion's founder, but he slammed the show for disrespect to organised religion. "There is a place in this world for satire, but there is a time when satire ends and intolerance and bigotry towards religious beliefs of others begins," he said.

But the South Park co-creator Matt Stone retorted: "In 10 years and over 150 episodes of South Park, Isaac never had a problem with the show making fun of Christians, Muslims, Mormons or Jews. He got a sudden case of religious sensitivity when it was his religion featured on the show."