Isaac Hayes died on Sunday at the age of 65 in Memphis. The legendary soul singer was found unconscious in his home, next to a still-running treadmill, before being taken to a hospital. The cause of death is still unknown.

Hayes, a Rock and Roll Hall of Famer and Grammy winner, was as influential a musician as any, having saturated Stax Records with his soul-funk cuts, which included the seminal soundtrack hit, 'Theme from Shaft.' He also wrote, with David Porter, several soul smashes for Sam & Dave, including 'Hold On, I'm A-Comin'' and 'Soul Man.'

Hayes was largely credited with influencing both disco and rap, before either genre even existed. His career saw a significant resurgence in the 1990s when he appeared as the voice of Jerome "Chef" McElroy on the popular cartoon 'South Park.' Hayes, whose own lyrics were sometimes seen as controversial (including his song for the show, 'Chocolate Salty Balls'), eventually left 'South Park' when an episode poked fun at the Church of Scientology, of which Hayes was a member.

His live shows were legendary spectacles and his catalog will be permanently revered. "The other godfather of soul," Hayes' musical influence cannot be undermined.