"Willy Nelson once said, 'If you ain't crazy then there's something wrong with you'," recalls Mike Scott.

"People who describe artistic souls as mad or crazy must be very unimaginative 'cos, to me, being a creative person means I have to take unpredictable choices."

Often to the detriment of his career, Scott, founder and frontman of The Waterboys, has always followed his wildest instincts. In the mid-Eighties he switched from epic rock to Gaelic folk just as the band's success was drawing level with U2 and Simple Minds.

And in the early Nineties, at a time when the re-release of signature single The Whole Of The Moon once again saw them on the verge of the big time, he decamped to a spiritual retreat in Findhorn, Scotland.

"He is either madman or genius," Record Collector once declared, "depending on your point of view."

If you count those who have played live with the group, there are 30 Waterboys. Yet there has always only really been one - this long-haired Scotsman who performs, on stage, as though he were "dragging both band and crowd up some invisible ladder towards mythical redemption".

"To me there's no difference between Mike Scott and The Waterboys," he says. "They both mean the same thing."

Formed in 1983 and named after a Lou Reed song, the group's full, rich sound was soon dubbed "big music" after the title of their 1984 single.

But, as Scott explains, "when I wrote the song I meant not a form of music but seeing sacredness in the physical world. It was just coincidence that we were making very broad, cinematic music at the time."

Through paint-stripping rock 'n' roll and mythic narratives to masterful pop and acoustic soul, spirituality has always been a key influence on Scott's lyrics. In the Eighties, he discovered the world of spiritual literature - British author Dion Fortune and Paramhansa Yogananda, the Indian mystic - and he is currently studying, via an internet course, the teachings of American spiritualist David Spangler.

"Often in spirituality we look at the personality as being a hindrance, as though the good stuff is all up there somewhere," Scott explains. "Spangler teaches that, actually, who we are every day is worthwhile and a source of spiritual energy."

Reunited in 2000 with Irish fiddler Steve Wickham, last year The Waterboys released their first live album, the career-spanning Karma To Burn, which also saw the band playing some of Scott's Nineties solo material.

"When we brought in the new bass player and drummer I immediately felt we had the sound I'd been waiting for for a long time," says Scott. "So I asked our sound engineer to start recording the shows. They're both black boys from a black music tradition and they bring a funkiness that broadens the sound.

"They also both have this real versatility - from sensitive and subtle to bonecrunching, blood-curdling rock 'n' roll. "I just keep my head down and throw the songs out really, while the storm rages around me."

Starts at 8pm. Tickets cost £18 and £22, call 01273 709709.