Chatting over a beer the day before a recent concert at the Africa Utopia Festival at London's Southbank Centre, the Grammy award-winning bluesman is also remarkably laid back. He has no idea what he is going to play.

"I never have a set list," Mahal told Reuters in the deep, gravelly baritone that, along with superb musicianship, has been his trademark for around 50 years in the business. "It's all by feel".

The feel must have been good. The concert a day later was a rollicking affair of wailing classic- and twangy country-blues and a smattering of world-inspired music including a banjo romp Mahal called, tongue-in-cheek, Afro-Celtic.

Seeming at times to be almost pulling the strings off the guitar rather than picking them, Mahal bashed out old standards through "Natch'l Blues" and a sashaying "John Henry" to a "Corrina, Corrina" encore that left the audience hollering for even more.

"There's a couple of things that people can't do without," he said. "Food and music."

His presence in a festival dedicated to all things Africa (it includes a lecture on adoption entitled "Quick Hide Madonna's coming") may seem strange to those who know Mahal mainly from his U.S. blues.

But Mahal has spent many years investigating and enjoying the links between African, Caribbean and American music, an interest he partially puts down to a West Indian heritage on his father's side.

He thinks of world music as connecting him to his cousins. "It's what was always connected to me and what connects me to it," he said.

AFRICA ROOTS

Not that Mahal plays world music per se -- rather, he uses the rhythms and sounds of various regions as a basis for his own style of Americana.

An example was his funky rendition of "Zanzibar", performed with Senegalese singer Baaba Maal, who has also been performing at the festival.

While Maal's African chants and lyrics dipped and soared, Mahal managed to turn his guitar into a cross between a kora and a mbira -- a twang from Austin by way of Lagos, if you like.

This is not surprising, given Mahal's view of the global links between instruments and music.

"The finger-picking style the world came to use began in West Africa," he said. "I'm of the opinion that it moved north through Morocco to Spain."

The audience loved it -- and his imposing yet friendly presence on stage, laced with humor and a love of what he does for a living.

He has been at this for a long time, ever since the 1950s when his Springfield, Massachusetts, home had a welcome invasion of musical émigrés from the South that got him into music.

But at 70, he gives no hint of calling it quits. Indeed, he opened his concert with a warning that anyone expecting an aged, venerable bluesman to come on stage was in for a disappointment.

This was going to be "a party", he said. And it was.

(Reporting by Jeremy Gaunt, editing by Paul Casciato)

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