Four years ago it was all oversized lemons, giant video screens and generous portions of irony. Oh, and stadiums, writes Sky News Online reporter Rob Cole.

Now Ireland's most famous exports have gone back to basics. Intimacy is the buzzword. A stripped down stage the focus.

And having successfully applied for the position of the World's Best Rock Band, U2 are effortlessly going through the motions of shaming contemporaries half their age as the Elevation tour rumbles across the UK and Europe.

Hence, with the Earl's Court house lights still on for opening night of their four-date London showing, Bono and the boys stroll onto stage for what starts off like an informal jam in front of 18,000 fans. No mock Popmart shadow boxing, no kitsch cowboy costumes and no sound disappearing into the summer sky. Just pure, unadulterated rock. And with a roof, it's loud, very loud.

Elevation, Beautiful Day and Until the End of the World are rattled off before the pillaging of the 25-year back catalogue begins with the first show-stopper New Year's Day.

"The idea we would be playing here, it always occurred to us," Bono confesses to the crowd before New Year's Day, reminiscing of the days when as 18 and 19-year-olds the band stayed round the corner from Earls Court, playing lesser known, and less crowded venues.

Bono dedicates Kite, from the band's new album All That You Can't Leave Behind, to his father Bob Hewson, who is dying of cancer.

But it's the golden oldies that get the hands in the air. It's said you can't dance to U2 songs - but you can sure jump up and down a lot. Especially when Bono spends half the show stage diving, shoulder-surfing and cajoling a rain-sodden audience from the front of the specially-built Elevation heart that surrounds a few dozen punters at the front.

I Will Follow gets a near fanatical reception as it rolls into Sunday Bloody Sunday, the song Bono said the band would never play again following the Enniskillen bombing. Bob Marley's Get Up, Stand Up replaces the chant "wipe your tears away".