And yet, wherever they go, an aura of naffness hangs about them. Is it the name? Is it the bouffant hair and equine incisors so prominent in the early days? Those teeth, like wicket gates, haven't changed, and Barry still boasts a mane that bestows upon him the look of a troubled deity. Down the front, of course, the sight of the boys in the flesh caused women to overheat at the rate of one every 10 minutes, but from anywhere else you could only see them properly on video screens, with a backdrop of distant spires and the sombre Wicklow Mountains.
The brothers don't like touring, but with the Saturday Night Fever and Grease revivals, they'd be fools not to; an undemanding schedule will take them on to single shows in London, South America, Africa and Australia. It's an ambitious set, though, 40 songs all told. When they appear they slip instantly into their designated roles. If Barry is the prime mover and romantic, Robin is the beaky stoic and Maurice, whose hair appears to have been relocated to his chin, strides about in shades, fedora and trenchcoat, the Ringo Starr of the band.
With a mammoth set to get through, the Bee Gees don't do repartee and they're out the other side of "Massachusetts" and "I've Gotta Get A Message To You" before we know it. Then Ronan Keating wafts on to retread Boyzone's massacre of "Words". Keating is blond and cute, almost the ghost of Gibb sibling Andy, scenes from whose short life are played on the screens.
Bee Gees numbers are either strategic missiles or, during their mid- period, the work of catalepsy, and the show sags with "Our Love (Don't Throw It All Away)" until the band is dismissed and the brothers unite for the close harmony only they can do - "Too Much Heaven", "New York Mining Disaster, 1941" and the unbearably eloquent "I Started A Joke".
There's a break for the pipes and drums of the Manx national anthem (all three were born in the Isle of Man), then, with a sonic shriek, it's disco inferno. "Tragedy", "Grease" and "Jive Talkin' " come out fighting. "How Deep is Your Love" is angelic, and "Stayin' Alive" justifies the legend of the Bee Gees on its own - as the videos show Travolta's hips, Maurice and Robin intone the song's orgasmic falsetto cadence ("uh, uh, uh, uh") and Barry, eternally on helium, squeaks: "You can tell by the way I use my walk/I'm a woman's man/No time to talk." In the annals of pop history, this is buffed white soul nonpareil.