UNFORTUNATELY, it makes sense that the band who embodied rock'n'roll as a golden Californian ideal - beginning with surfing and hot rods and growing into a teenage symphony of love, heartbreak and wonder - should have the darkest legacy. Like Dorian Gray, the best music of the Beach Boys, and in particular Brian Wilson, the fragile genius at the band's centre, remains in pristine condition, a gorgeous soundscape of harmonies and instrumentation that remains deeply influential. But the band's picture - their tarnished history - is scarred by tragedy and vituperative conflict.
Acolytes of the Rolling Stones may venture Brian Jones' drowning, the murder of a fan at Altamont festival and the 1972 Exile on Main Street tour as evidence of decadence and decay. But an unabridged history of the Beach Boys includes a monstrous patriarch, mental illness, thwarted artistry, Charles Manson, the death of two of Brian Wilson's brothers and band mates, Dennis and Carl, and a labyrinthine legal history of strike and counter-strike. The group introduced the word ''dysfunctional'' to popular music.
Naturally, after all this, and just when they appeared to be solely the jurisdiction of archivists, lawyers and corporate minutes, the Beach Boys have re-formed for a 50th-anniversary tour and released a new album, That's Why God Made the Radio.
''It shows you how powerful the music is, that it can outweigh all that negativity,'' says Al Jardine, a founding member of the band and sometime songwriter and vocalist. ''Everybody has arguments - although they don't all necessarily end up in court - but the truth is that the message is so much bigger than the messenger. The music is all that really matters, and the music will be our legacy.''
It is the day before the reconvened Beach Boys play a home-town show in Los Angeles, and the 69-year-old is doing what he's done for much of the past five decades: trying to find a middle ground. In this case it's negotiating a mass of ticket requests from family, friends and industry colleagues, but for much of the band's existence Jardine has served as negotiator and liaison.
Given that one of Brian Wilson's signature compositions is 1966's Heroes and Villains, the Beach Boys have always been seen through the prism of him as the preternaturally gifted artist who collapsed under the weight of his genius, with his cousin and fellow founding member, Mike Love, the hard-nosed businessman determined to ensure terms profitable to himself and willing to sue anyone, including family and band mates, to make it happen.
''It's difficult, very difficult,'' concedes Jardine, who last faced Love in court in 2008 when Jardine toured as the Beach Boys Family & Friends and Love sued for breach of title use. ''But Brian has been sued by him, too.
''Lots of people have been on a legal docket with Mike Love. It's probably a badge of honour.''
It was Jardine who kept at Wilson and Love throughout 2010 and last year about the group's legacy and the commercial possibilities of a world tour. Joined by David Marks, an early member from the band's Californian home of Hawthorne, who left and rejoined several times in the early 1960s, and Bruce Johnston, who came on-board in 1965 to replace Brian Wilson in the group's touring line-up, the new-look band now has the chance to play songs such as Good Vibrations, Sloop John B, I Get Around, God Only Knows and Surfin' USA once more.
''They each have a fairly successful touring apparatus of their own, but they couldn't ignore the 50th anniversary,'' Jardine notes with satisfaction. ''They knew it and I knew it. It was just a matter of time to get them around the table and make some concessions to one another. That's how it works: you all have to give something to get something.''
Under immense pressure, Brian Wilson had his first nervous breakdown in 1964, on a flight from Los Angeles to Houston for a show, and he's been wary of touring since. But the 70-year-old, who is one of the leading American songwriters of the 20th century, is fully committed to the current, extensive run of dates, according to Jardine.
''He loves to get out on the road now,'' Jardine says, ''and it's astonishing to hear Brian Wilson singing like he's 19 or 21 again. I sing an old American classic called Cotton Fields and I did the arrangement for the band, and he just loves that. He can't get enough of it. Brian says it reminds him of his childhood, and that's a therapy for him.''
Wilson lost much of the 1970s and '80s to drug abuse and mental illness, ballooning to become an overweight, bathrobe-clad recluse who hardly set foot inside a recording studio. He eventually returned to a more stable life, which involved years with therapist Eugene Landy, who many considered a controlling force on Wilson before he lost his psychology licence and was placed under a restraining order.
''I really didn't think we'd get him back,'' Jardine says of Wilson. ''He looked pretty much like he was finished. We almost lost him a couple of times, literally, and somehow it's a miracle that Brian has survived his entire family - they're all gone now, apart from his children.''
The lush production and nostalgic sounds of That's Why God Made the Radio, put together by Wilson with input from his band mates, work as a kind of time machine. The album takes listeners to the first few heady years when Jardine quit but soon returned (in 1963) and decided to spend his life making sense of what he was a part of.
''I've been the outsider looking in all these years,'' he says. ''It hasn't been easy, because like any tight-knit group, family looks after family. I had to be pretty patient at times, and forgiving, and persevering. Blood is thicker than water - with the Beach Boys, it's biblical.''
■The Beach Boys play Rod Laver Arena on Friday, August 31.