This brief musical fragment provides the basis, in sampled form, for a whole song on both Portishead's Dummy and Tricky's Maxinquaye, the two most innovative British albums of recent times. Indeed, Hayes is one of the most sampled of all popular artists after James Brown - revered by just about the whole hip-hop nation from West Coast gangstas, like Snoop Doggy Dogg, to the more benevolent Arrested Development.
Imposing, soft-spoken, with a voice pitched so low that dogs can't hear it, Isaac Hayes has a big and important history: from Tennessee sharecropper's son to Ghanaian king, via soul, civil rights and Shaft. He also has a new record deal and an album, Branded, his best in a decade. It includes a certain hit version of John Sebastian's "Summer in the City", taken from the Die Hard soundtrack, as well as several new Hayes compositions, one of which features the immortal line, "I can be sweet or nasty, rough as a bear or gentle as a dove".
You might have seen Hayes on the Brit Awards, being shamelessly schmoozed by Chris Evans. If Hayes detects a whiff of condescension, he does not show it; he is very generous in sharing his memories. "My first recollection of singing publicly", he begins magisterially, "was in church, across the road from where I lived in the country, when I was three years old. I made my public debut singing on an Easter programme with my sister, and my grandmother played piano. It was funny, because my sister screwed up on a harmony in the middle of the service and, not knowing any better, I said, `No, stop, you don't do it that way - it goes like this'. Of course, everybody thought that was cute."
Despite his classically Deep South musical background - singing on the porch, uncles playing the blues, that kind of thing - Hayes says he first wanted to be a doctor. But, in his early teens, he won a talent contest in Memphis. "I got the bug," he says.
There were several false starts. He toured the churches of Tennessee, Mississippi and Arkansas, singing bass with a gospel group, the Morning Stars; then with a blues band, Calvin Valentine and the Swing Cats; and even a doowop vocal group, the Teen Tones. In 1962, as Sir Isaac and The Doodads, he cut an unsuccessful single called "Laura, We're on our Last Go-round". He did not hit his stride until he joined the Memphis Stax label as a session sax player and keyboard deputy for Booker T Jones, of "Green Onions" fame.
It was at Stax in 1964 that he perfected his much-copied look of bald head and whiskers. He went round the corner from Stax to Mr King's barber shop, shook his locks loose from his stocking cap, and asked Mr King to cut them all off. "People used to laugh at me - `look at that bald-headed guy with the beard!' - but they don't laugh now."
Of more significance was his new songwriting partnership with David Porter, with whom he would pen more than 200 songs, including the huge hits "B- A-B-Y" and "Soul Man", for Stax artists such as Carla Thomas and Sam & Dave.
For each of these songs, there is an anecdote. He recalls, for example, that the inspiration for writing the soul classic, "Hold On, I'm Coming", sprang from his partner's visit to the toilet. "I was shouting `come on back, David - I've got something', and he called out, `hold on, I'm coming'; then he came running back, yelling `that's it! That's it!'"
In those days, the Lorraine Motel, now Memphis' grimmest tourist attraction, was the scene. "A lot of the artists who came to Stax stayed there and, in the summertime, when it got too hot to record, we'd take off, swim in the pool and eat chicken." If his then wife had not insisted on taking the car that day in 1968, Isaac Hayes would have been pulling up at the Lorraine Motel right about the time Martin Luther King was assassinated. For about a year after this, Hayes found it hard to write - to do anything, even. "I was bitter. It was like everything was dead - all our hopes were gone. Man, it was a dark time."
In 1969, however, he released his second solo album, Hot Buttered Soul, one of the most influential pop records ever. His extended arrangements of classic songs like "Walk On By" paved the way for disco music - and Barry White in particular; and his story-telling prologue to Jim Webb's "By The Time I Get To Phoenix" is now regarded as one of the first rap records.
But Hayes is most closely associated with blaxploitation films, specifically his soundtrack in 1971, for Gordon Parks's Shaft, the black private eye. Hayes, influenced by Quincy Jones's work on films such as McKenna's Gold, produced a soundtrack so popular that, eventually, it out-grossed the phenomenal success of the film itself. It also initiated a new career for Hayes as a film actor, usually as a street heavy (The Rockford Files, Escape From New York), but most recently as a cowboy in Posse (made by Mario Van Peebles, whose father, Melvin's, film, Sweet Sweetback's Badass Song, started the whole blaxploitation genre).
Bankruptcy and divorce have dogged Hayes in recent years, and out of spiritual need he has joined John Travolta, Juliette Lewis and Tom Cruise in the ranks of Hollywood scientologists. But these reverses must be set against a most unexpected honour: his coronation in Ghana last year. He has been installed as king, with the name Nene Katey Okanseh, of the Ghanaian region of Ada, an hour's drive east of Accra, and is charged with bringing development to the area. "If kids of other ethnicities learned about our African heritage - that we had dynasties and cultures long before slavery - they would have more respect for us, and we would have more respect for ourselves, and we would all get along much better," he says.