Aloof from the linear motion: Allen Toussaint is the man they say invented funk. Philip Sweeney met him in New Orleans

No city's contribution to American popular music is more distinctive than that of New Orleans, and no New Orleans' musician personifies more facets of its output than Allen Toussaint, who helps to kick off the South Bank Centre's American South Festival at the Queen Elizabeth Hall tonight.

Toussaint's career is a dense gumbo, packed with hundreds of hit compositions, productions and arrangements for everyone from Ernie K-Doe to Elvis Costello, but spiced only sparingly with live performances ('Even my top year wouldn't hardly exceed eight shows,' he says). This London concert, then, is a collectors' item.

Born poor in 1938, Toussaint (he pronounces it like Tucson, Arizona) played piano for money in neighbourhood bars at the age of 12, ghosted keyboard tracks for Fats Domino (at the behest of the legendary producer, Dave Bartholomew) within a few years, and recorded his first album, under the name of Al Tousan, by 1958. In the mid-Sixties, after National Service, Toussaint and his partner, Marshall Sehorn, set up Sansu Enterprises and embarked on the virtual creation of New Orleans' soul with artists such as Lee Dorsey, Irma Thomas, the Meters and later Dr John. Toussaint's productions, simple and utterly rhythmic with a spare, exact snare-drum, clicking guitars and sleazy minimalist horn sections were completely transparent yet practically inimitable.

By the early Seventies, mainstream artists - Paul McCartney, Robert Palmer - were heading for 3809 Clematis Avenue, New Orleans - where Toussaint had established his Sea-Saint recording studio - for an infusion of funk.

You still contact Toussaint at Clematis Avenue, where his daughter Alison handles admin and his son Clarence is house producer. When I called, Toussaint was about to start recording a new album, only his sixth ever. He is courteous, straightforward and soft-spoken, even when a note of enthusiasm - 'Oh] Yes]' - raises the inflection of a response.

Would Toussaint consider himself the creator, in effect, of modern New Orleans funk? 'Well, I've been charged with that, and I like the charge . . . I wouldn't have stated that myself, because I was just busy making music, I didn't analyse it.'

What is unique about New Orleans music? 'I don't critique New Orleans music by saying it's got something other areas don't have, but I can appreciate a uniqueness to it. I think it's because of our geographic locale - we're located a bit aloof from the linear motion across the nation; down South, we're off the beaten path. That's contributed to us holding on to traditional parts of our music.'

Does the second-line rhythm - the sashaying march beat of the second line of mourners at a jazz funeral - contribute? 'There are some key elements in a second- line rhythm - actually there are two rhythms, the very slow, mournful mode, usually 12/8, on the way to the funeral, and on the way back, a struttin' inspired type of march. The second-line rhythm is very simple to those who were born to it, but once you put it down on paper, it gets very complex because of the syncopation. Many New Orleans songs don't actually use the second-line beat, but it's kind of there subterraneally in spirit.'

What was the origin of the word 'funky'. It was used in jazz circles in the 1950s. Did it come from New Orleans? 'Certainly we were using it locally a long time before it became national. I was very surprised to see it picked up on TV. I thought it was a little guttural for the national scene. It was kind of a barrelhouse music that inspired risque movement in the body.'

Toussaint's first Number One hit as composer / producer / arranger was Ernie K-Doe's immortal 'Mother-in-Law' in 1961. How did the making of that record go? 'It was very easy. I was working for Joe Banashak, founder of Minit Records. I wrote the song in 20 minutes. The horn part only had four notes - in fact I used the same horn charts I'd used earlier in the day on another song, 'Ain't it the Truth'. I remember in the studio we were singing it much faster than it came out, and Banashack called, 'Could y'all slow it down, it's movin' by me too fast.' So we did, and that's what put the magic to it - the right tempo.'

What about Lee Dorsey, the boxer, car repairer and singer who died of emphysema in 1986 and gave Toussaint's fledgling Sansu label its first great hits in the Sixties - 'Ride Your Pony', 'Working in a Coal Mine', 'Holy Cow' etc? 'Oh] Yes] That was a great time for us. Lee Dorsey was wonderful to work with, and we did lots of other things together; we'd go out in the evenings, double- date, ride motorcycles together. It's hard to imagine him no longer here; he had such a lively voice.'

It was out of those early Dorsey sessions that the Meters came together, 15 years before they became the Neville Brothers. 'Oh] Yes] We discovered the Meters working down on Bourbon Street around '65. They were Art Neville and the Neville Sound, then. We invited them to come over to record and they decided to be a cooperative group, so we came up with the name the Meters; really a most magical group.'

And Toussaint's two classic Dr John albums, Right Place, Wrong Time and Desitively Bonnaroo? 'Jerry Wexler of Atlantic Records put us together. He might be one of the most knowledgeable men in all existence on what kind of musical gumbo to stir up. It was a natural combination. Mac (Rebennack, aka Dr John) and I are from the same background, we've the same musical heroes - those recordings had lots of elements conducive to magic. We recorded in Miami by the ocean where I could rewrite arrangements in the evening. How could you go wrong? The same elements came together for Southern Nights, my best album. it was a good period for liquid motion in music.'

The American South Festival runs at the South Bank until 30 July (booking: 071-928 8800)