After performing "Theme From Shaft" in aviator shades, a metal mesh shirt and a hefty gold chain, Isaac Hayes approached the podium at 1972's Academy Awards. His shaved head gleamed in the spotlight as he accepted an Oscar for Best Song — and paid tribute to the most important woman in his life. "I'd like to thank the lady who's here with me tonight, my grandmother," Hayes said, his baritone softening as he addressed the woman who raised him. "Years ago, her prayers kept me on the path of righteousness."

That was Isaac Hayes: bad motherfucker, sensitive dude. Hayes — who died at home in Memphis on August 10th of a stroke at the age of 65 — was also a musical and cultural innovator whose influence spanned decades, extending from his genre-defining work for Memphis soul label Stax Records to his self-parodying role as Chef on South Park. "Music just oozed from him — it was second nature to him," says Alicia Keys, who inducted Hayes into the Rock & Roll Hall of Fame in 2002.

Hayes first came to prominence in the mid-Sixties, writing and producing Sam and Dave's biggest hits ("Soul Man," "Hold On, I'm Comin' ") with his then-partner David Porter, while also playing keyboards on countless Stax tracks. He cut the first blockbuster R&B album, Hot Buttered Soul; presaged the sound of disco with Shaft's hypnotic high-hats and syncopated horn blasts; and along the way became an icon of proud black masculinity, known for a time as Black Moses, the name of his 1971 double album.

Hayes, orphaned as a baby, moved with his grandparents from rural Tennessee to Memphis at the age of seven. He picked cotton and worked in a slaughterhouse before joining the staff at Stax — initially as a replacement for Booker T. and the MG's keyboardist Booker T. Jones, who had headed off to college. Earlier, Hayes had auditioned for Stax as a singer, but owner Jim Stewart turned him down — his Nat "King" Cole-influenced crooning was far from the soul shouting Stax favored. But once Hayes found his way in, he made the most of it. "It was like my class," he told Rolling Stone in 2005. "I was learning everything about record production. I was just watching every move the guys made."

He soon began writing with fellow Stax staffer David Porter, huddled over a piano in their small office. They found their niche in the gospel-influenced call-and-response style of Sam and Dave. "He was the catalyst, the designer, for Sam and Dave," says Sam Moore. Hayes, a Burt Bacharach fan, also broadened Stax's sound. "He was able to throw in jazz-type chords and make them funky," says MG's guitarist Steve Cropper, who recruited Hayes for Stax after seeing him play with a jazz band.

Hayes was always a formidable presence, especially after he started shaving his head in 1964. "He was one of the most unique human beings I had ever seen," says Al Bell, who ran Stax during Hayes' later solo success. "Isaac would come in with a purple shirt on, some pink pants, yellow socks and blue shoes." When Hayes played clubs in Memphis, Bell was struck by the spoken-word intros he would improvise as the band vamped — and by the reaction they sparked. "All he was really doing was hitting on the girls," Bell says. "He'd get their attention, and some young lady would leave with him."

Hayes made a quickie album, Presenting Isaac Hayes, in 1967, but his solo career truly began with 1969's Hot Buttered Soul — four lengthy, spectacularly orchestrated tracks. And on his 18-minute-plus cover of Glen Campbell's "By the Time I Get to Phoenix," he debuted the seductive spoken-word segments that he called "raps."

The result was psychedelic lovemaking music, and it was a smash, creating a market for R&B albums. "I cut that record with all the freedom in the world," Hayes told Rolling Stone in 1972. "And it was a beautiful release for me." The next few years were heady for Hayes — he became a superstar with the Shaft soundtrack, which combined funk and social commentary — and for a while, he surrounded himself with gun-toting cronies.

By 1976, the hits stopped coming. Hayes was $6 million in debt and filed for bankruptcy. Even as his music was heavily sampled in hip-hop, he spent much of the Eighties and Nineties focused on acting, going as long as seven years between albums. It wasn't until he landed his role as Chef on South Park that he reached a new generation. "You work all your life, struggle for excellence, and then some wack cartoon happens, and you're hotter than you've ever been," he said in 1999. Hayes, who became a Scientologist in 1995, quit the show in 2006 after it mocked the religion. That same year, he suffered a stroke, scotching what Cropper says were plans for a Stax reunion tour. Despite what friends say were ongoing health problems, he returned to the road over the last two years.

At his peak, Hayes was more than just another musician. "He was a cultural icon, come from within our midst," says Booker T. Jones. "He symbolized hope for a lot of people."