FEW albums have had as traumatic a genesis as Smile, the Beach Boys' legendary "lost" follow-up to Pet Sounds.

Brian Wilson, the genius who had transformed the Beach Boys from purveyors of feel-good, sunshine-splashed pop to the Beatles' only serious creative rivals, was halfway through the recording of his "teenage symphony to God" when his world caved in.

Despite the ecstatic nature of the music he was making - Good Vibrations and Heroes and Villains were two of the songs to have featured in the album's provisional track-listing - Wilson was a far-from-happy man.

In 1964, stress had led him to retire from touring with the band and concentrate on writing and producing their records instead.

Two years later, in response to the release of the Beatles' Rubber Soul, he started work on Pet Sounds - an album he hoped would match the Beatles for sonic innovation and emotional maturity.

Having achieved precisely what he set out to (Paul McCartney even hailed God Only Knows, one of Pet Sounds' many spiritually uplifting tracks, as his favourite song ever), there was no chance for Wilson to rest on his laurels, as the Beatles, themselves spurred on to greater things by the glorious Pet Sounds, threw down their next challenge - Sgt Pepper's Lonely Hearts Club Band.

That was when Wilson (pictured) came up with the idea for Smile, an album that would be the purest expression yet of his art and soul.

But, after several months of intense work with lyricist Van Dyke Parks, and with the weight of the world's expectations on his shoulders, Brian abandoned the project.

The combination of LSD, over-work and the pressure to deliver was just too much.

"I retired for about three months. I didn't do anything. It was hard for me to live up to my name," says Wilson, who maintained his creative links with the Beach Boys, but shunned publicity and retreated into a mental world of his own.

In recent years, the revered writer, producer, arranger and performer has returned to the public arena and talked openly about his troubled past, which reduced him to a state of helpless, child-like inertia - to the point where he built a sandpit in his living room and spent the best part of a decade in his pyjamas.

Last year, he delighted fans by going out on tour with Pet Sounds. Now he has started another round of live dates.

Talking exclusively ahead of one of his concerts, he says simply: "I figured it was time for people to hear it."

This is a busy time for Wilson. In addition to the live dates - which he previewed in February with a rapturously-received set at London's Royal Festival Hall - he has released his first new studio album in six years, Gettin' in Over My Head, and brings out an all-new studio recording of Smile on September 27.

As well as being a "teenage symphony to God", Wilson describes Smile as "a three-movement rock opera".

Against expectation, he says the decision to revisit the album was not a hard one.

"I just made the decision one day and took the old tapes and put it all together. It brought back memories - some of them about drugs.

"I'm thrilled with it, though. It's probably one of the best things I've done."

Better even than the Beatles album he was trying to trump in the first place?

"I think Sgt Pepper's is better than Pet Sounds, but I think Smile is better than Sgt Pepper's."

Showcasing the songs from the album to the public for the first time was not quite such a breeze, however.

"When we took it to London, I was very nervous. The reception was great, though. I was very proud of the 10-minute standing ovation."

Wilson has acknowledged his debt to Paul McCartney by featuring him on Gettin' in Over My Head, along with fellow musicians like Elton John and Eric Clapton.

"I just called them up and asked them," he says. "They're not all friends, but Paul McCartney is. He turned me on to some great music."

Since the mid-'90s, when he married for the second time, Wilson has been making enormous strides in putting his life back together. The demons of the past seem to have been banished for good, although the ravages of mental illness and drugs are still there in his robotic-sounding voice and slightly distant manner.

"I've finally reached the point where I'm really happy," he says.

You're forced to take his word for it, really - but if his current level of productivity and publicity is anything to go by, he means it.