Isaac Hayes by James Sharrock/WireImage.com Isaac Hayes by James Sharrock/WireImage.com
Isaac Hayes, the legendary soul singer and songwriter who won an Academy Award for the theme from Shaft and voiced the character of Chef on the animated show

South Park, has died, authorities said Sunday. He was 65. Hayes' wife found him unresponsive near a treadmill in his Tennessee home and he was later pronounced dead at a Memphis hospital, the Shelby County Sheriff's Office said. The cause of death was not known and no foul play was suspected. The self-taught musician was a pioneer in the 1960s, writing hit songs with David Porter for Sam and Dave, such as "Hold On, I'm Coming" and "Soul Man." In the 1970s, he laid the groundwork for disco. His "Theme from Shaft" hit the top of the charts in 1971, earning him two Grammys and an Oscar for best original theme song. Hayes performed the song at the 1972 Oscar ceremony, wearing an eye-popping amount of gold and received a standing ovation. TV Guide later chose it as No. 18 in its list of television's 25 most memorable moments. ''Isaac Hayes embodies everything that's soul music,'' Collin Stanback, an A&R executive at Stax Records, told the AP on Sunday. ''When you think of soul music you think of Isaac Hayes - the expression... the sound and the creativity that goes along with it.'' Hayes was about to begin work on a new album for Stax, the soul record label he helped to build. And he had recently finished work on a movie called Soul Men in which he played himself, starring Samuel Jackson and Bernie Mac, who died on Saturday. The crooner was inducted into the Rock and Roll Hall of Fame in 2002. He also was known for lending his deep voice to the character Chef, a devoted ladies man and school cook, in the TV show South Park. But the Scientologist quit the series in 2006, saying he could no longer stomach its take on religion. A few months earlier, South Park had targeted the Church of Scientology and some of its celebrity followers, including Tom Cruise, in a top-rated show called "Trapped in the Closet." - Jennifer Holland