Isaac Hayes, who has died aged 65, earned massive international acclaim and a niche in the record books from writing the Oscar-winning theme for the movie Shaft in 1971. But that was only the tip of the iceberg of Hayes's talents, which comprised skills as a multi-instrumentalist, producer, arranger and vocalist, as well as composer, songwriter and actor. The musical innovations he pioneered throughout his career made him an influential figure in the development of soul and disco, and he was later dubbed the "Original Rapper". He was inducted into the Rock and Roll Hall of Fame in 2002.
Born in Covington, Tennessee, Hayes was raised by his sharecropper grandparents in their shack after his mother had died and his father walked out. When he moved with his grandparents to Memphis, he took jobs as a bus boy and dishwasher to help boost the household's dire finances, but it was a sign of things to come when he won a talent show singing the Nat King Cole hit Looking Back. "Career change!" recalled Hayes, whose only previous musical experience was singing in church as a boy. "I started pursuing music big time."
He began finding work as a musician in local clubs and formed several shortlived groups, including Sir Isaac and the Doo-Dads and Calvin Valentine and the Swing Cats. Then he signed on as pianist with saxophonist Floyd Newman, who was also a staff musician for the new Memphis label, Stax. This brought Hayes an invitation to stand in on keyboards for a temporarily absent Booker T Jones, from the Stax house band Booker T & the MGs, and he played his first paid sessions with Otis Redding in early 1964.
Hayes had become a familiar face around Stax when the writer and producer David Porter suggested they collaborate as songwriters. It was an inspired move, and soon the Porter/Hayes duo (alias the Soul Children) were banging out such classics as Soul Man, When Something Is Wrong With My Baby and Hold On, I'm Coming for Sam & Dave, and the sublime B-A-B-Y for Carla Thomas. Hayes's work at Stax helped to create the Memphis Sound, which influenced the Beatles, the Rolling Stones and almost everybody who mattered in pop.
The assassination of Martin Luther King in Memphis on April 4 1968 was especially shattering for Hayes, who had joined King's civil rights marches and was due to meet him on the day of his death. "I thought 'I can't do a thing about it, so let me become successful and powerful enough where I can have a voice to make a difference.' " His first solo album, Presenting Isaac Hayes, was released that year. It sold insignificantly, but his 1969 follow-up, Hot Buttered Soul, sold 1m copies and represented a bold artistic advance. It contained only four tracks, and its complex symphonic arrangements and verbal monologues pointed the way ahead to 1970s concept albums by Marvin Gaye, Barry White and Stevie Wonder. His expanded versions of Burt Bacharach's Walk on By and Jimmy Webb's By the Time I Get to Phoenix still sound revolutionary.
Hayes's Shaft moment duly arrived in 1971, and his double-album soundtrack made him the first African-American to win an Academy award. The Theme from Shaft, with its tense beat, edgy wah-wah guitars and effortlessly hip monologue, became a Grammy-winning chart-topper, made No 4 in the UK and made Hayes a global star. He was the godfather of bling in his gold chains and interplanetary costumes, as well as one of the most imitated musicians on the planet. He was showered with film and television work, scoring the TV show The Men and the movies Tough Guys and Truck Turner (both of which also starred Hayes, who played a bartender in Shaft). His Truck Turner score would be used by Quentin Tarantino in his Kill Bill movies. In 1974 he debuted in the recurring role of Jim Rockford's fellow ex-con in The Rockford Files.
Hayes released a second successful double-album in 1971, Black Moses, and his US chart-topping Live at the Sahara Tahoe made it three. His 1973 album Joy included the hit I Love You That's All, later sampled by numerous artists, including Massive Attack and Eric B & Rakim.
In 1975, following a struggle with Stax over royalties, Hayes set up his own Hot Buttered Soul (HBS) label, under the wing of ABC. He scored a big hit with the disco-orientated Chocolate Chip, though follow-ups Disco Connection and Groove-A-Thon proved less commercial. By 1976 he somehow found himself $6m in debt, and was mortified to see his solid gold Cadillac Eldorado go to the tax authorities.
However, he lost no time in staging a comeback, teaming up with Dionne Warwick for the 1977 double-LP A Man and a Woman, and co-writing Warwick's US Top 20 hit, Déjà Vu. Hayes signed a solo deal with Polydor and notched hit singles with Zeke the Freak, Don't Let Go and Do You Wanna Make Love. The last of these was from his final 70s album, a duet with Millie Jackson called Royal Rappin's (1979).
The 1980s proved unrewarding musically, but Hayes compensated by stepping up his acting work. He played the villain in John Carpenter's Escape from New York, appeared in action romps Counterforce and Dead Aim, and adorned the small screen in The A-Team, Hunter and Miami Vice. In 1988, he appeared in the Keenen Ivory Wayans comedy I'm Gonna Git You, Sucka, a satire of Shaft-style blaxploitation films.
Numerous film parts followed through the 1990s. Hayes now signed a record deal with Columbia. His album U-Turn contained Ike's Rap, featuring a powerful anti-crack message ("Don't be a resident of crack city"). He also agreed to lecture in colleges in prisons about the perils of drug addiction.
In 1992, Hayes explored his humanitarian bent further when he and Warwick accepted an invitation to visit the Cape coast and the Elmina slave castles of Ghana. Much moved, Hayes committed himself to raising funds to improve social and educational standards in Ghana. He was rewarded by being made a Ghanaian king. He subsequently founded the Isaac Hayes Foundation, to promote literacy, musical and nutritional education around the world. He was an enthusiastic chef who owned restaurants in Memphis and Chicago, and often performed at both.
In 1997, his culinary leanings led to his being cast as the voice of Chef in the animated TV show South Park. Hayes described the character as "a person that speaks his mind; he's sensitive enough to care for children ... And he loves the ladies". Chocolate Salty Balls (PS I Love You), a song performed by Chef, was his first UK chart-topper. However, he left the series acrimoniously, apparently offended by an episode that satirised Scientology, which he espoused and promoted. South Park's creators, Trey Parker and Matt Stone, argued that Hayes had not objected to other religions being lampooned, but wanted to apply different standards to Scientology.
Hayes suffered a stroke in 2006, and appeared confused and disorientated on a TV talk show earlier this year. Last Sunday, he was found unconscious by his wife Adjowa at his home near Memphis, apparently having collapsed while using a treadmill. He was pronounced dead at Memphis's Baptist Memorial hospital, and was thought to have suffered a simultaneous stroke and heart attack. Adjowa was his fourth wife. He fathered 12 children.
· Isaac Hayes, musician, born August 20 1942; died August 10 2008