By Chris Heard
BBC News Online entertainment staff
Beach Boys co-founder Brian Wilson is in the UK to perform his mythical "lost" album Smile live for the first time.
Smile holds a particular fascination for Wilson fans
Smile had been due for release in January 1967 at the height of Wilson's creative genius and a few months ahead of rival band The Beatles' groundbreaking Sergeant Pepper album.
But its 24-year-old composer suffered an emotional breakdown amid tales of drug-fuelled paranoia, and the record was never completed.
A few months ago Wilson revisited the Smile tapes in Capitol Records' vaults and went on to finish the album with his original lyricist, Van Dyke Parks.
Negotiations are said to be under way for an album release, and on Friday Wilson begins a 12-date UK tour of Smile beginning with six nights at London's Royal Festival Hall, backed by Los Angeles band The Wondermints.
Nearly 40 years on the album has acquired a legendary status among fans as probably the greatest unreleased record in rock history.
"There's nothing that comes close to its reputation," said Alexis Petridis, rock critic for The Guardian and Wilson enthusiast.
Wilson (left) stopped touring with the band in favour of the studio
"There's nothing else like it, there's no long lost Beatles album.
"The feeling is among some ardent Beach Boys fans that if it had come out when it was supposed to, the whole course of rock music may have been changed."
Smile was designed to be a concept album built on Wilson's visions of two themes, the historical expansion of America and the natural environment.
In the absence of touring fellow Beach Boys, Wilson collaborated with Van Dyke Parks, beginning work in 1966 at his Los Angeles home in the febrile atmosphere of the California counter-culture.
Songs such as Heroes and Villains and Surf's Up emerged from the sessions, but the full-length album never materialised as planned.
Many believe it might have gone on to eclipse Sergeant Pepper's Lonely Hearts Club Band - widely regarded as the defining record of the psychedelic era.
Wilson was competitive with The Beatles, and his previous work Pet Sounds - often called the greatest rock album ever - had been egged on by Lennon and McCartney's rapidly-developing songwriting craft.
Wilson has re-emerged with his legend in tact
Like Smile, Pet Sounds had marked a departure from the well-trod Beach Boys path of sunshine, surfing and girls towards a more introspective form of songwriting that seemed at odds with its radio-friendly predecessors.
Wilson was also mastering the art of the studio like no other producer since his other great hero Phil Spector, whose pure girl-group pop sound had such an impact on the Beach Boys.
It was during the Pet Sounds/Smile era that many critics say Wilson revealed himself to be a prodigious composer and arranger, with an ear for orchestral complexity comparable to a Mozart or Beethoven.
"What is fascinating is that Smile is utterly unlike any other music either the Beach Boys or anyone else has ever produced," said Mr Petridis, who rates Wilson as the 20th Century's greatest songwriter.
"It's unique, incredible in scope and impressionistic in style. The music is miles away from anything, apart from perhaps the compressed version of Americana of the Flaming Lips and Mercury Rev."
Some of the Smile songs have appeared in different forms on singles, later albums - and on several bootleg recordings in the 37 years since it was completed.
In 1988 the band were inducted into the Rock & Roll Hall of Fame
Among them were four tunes written inside an 80-square foot sand-box in Wilson's living room, installed "to recreate the feeling of being at the beach and the ocean".
The sand-box that has become part of Wilson folklore was one of a series of eccentric events which characterised the recording of Smile.
For the track Vegetables, session musicians harmonised on various foods of the earth, including a carrot munched on by a passing Paul McCartney.
During the song Fire - part of a planned "Elements" suite - Wilson set a studio bucket alight and sent out to a toy store for fire helmets for the orchestra to wear.
The project was shelved amid Wilson's punishing work schedule, inter-band bickering and friction between the group and their label.
Wilson spent several years as a virtual recluse until re-emerging in 1988 with a well-received solo album. A decade later he made a triumphant return to the stage, culminating in his critically-adored Pet Sounds tour of 2002.
Alexis Petridis said the Smile shows would be fascinating, but warned: "The danger is that the expectations are so enormous that the album can't ever really hope to live up to it."