The talented singer, songwriter and composer, who won the Oscar in 1972 for best original song for the theme from "Shaft," was found unresponsive at his house by family members, Shelby county sheriff's spokesman Steve Shular told AFP.
Hayes was discovered at about 1:00 pm (1800 GMT) collapsed on the floor of a bedroom in his home next to a treadmill that was still running, he said.
"We don't believe there was any foul play," Shular said. "Based on the statements by family members that Mr. Hayes had been treated of late for a number of medical issues, we believe that led to his death today. There are no plans for an autopsy."
Before the days of rapper Jay-Z crossing over music and basketball, there was Hayes. The singer, who was most recently famed for his voicing of the "Chef" character on South Park, bought into an American Basketball Association team in the 1970's (per wikipedia):
On July 17, 1974 Isaac Hayes, along with Mike Storen, Avron Fogelman and Kemmonis Wilson took over ownership of the American Basketball Association team the Memphis Tams. The prior owner was Charles O. Finley, the owner of the Oakland A's baseball team. Hayes' group renamed the team the Memphis Sounds. Despite a 66% increase in home attendance, hiring well regarded coach Joe Mullaney and, unlike in the prior three seasons, making the 1975 ABA Playoffs (losing to the eventual champion Kentucky Colonels in the Eastern Division semifinals) the team's financial problems continued.
In a scenario reminiscent of that portrayed in Will Ferrell's comedy Semi-Pro, the team was faced with a tough fight for survival:
The group was given a deadline of June 1, 1975 to sell 4,000 season tickets, obtain new investors and arrange a more favorable lease for the team at the Mid-South Coliseum. The group did not come through and the ABA took over the team, selling it to a group in Maryland that renamed the team the Baltimore Hustlers and then the Baltimore Claws before the club finally folded during preseason play for the 1975-1976 season.
See the complete history of the Memphis Sounds at RememberTheABA.
Hayes was married four times and fathered 12 children, according to US magazine. He is survived by his current wife Adjowa, whom he married in 2005 and with whom he had one child.