When a rock band plays one of London's classical venues, it's frequently a signal that said rock band are taking themselves very seriously indeed. The audience must sit in rapt silence while the band purvey their art, the grandeur of the surroundings is at odds with a rock gig's visceral thrills, and the outcome is dry and bookish, like attending a dull-but-worthy lecture.
Yet Meltdown, the Royal Festival Hall's annual concert series picked by a left-field rock dignitary, regularly surprises. The catholicism of the directors' tastes often leads to genuinely wayward moments. Last year, Scott Walker was curator. Among his choices was an Austrian industrial band called Fuckhead, who concluded their set by stripping naked, sticking a washing line up their bums and hanging clothes off it. That has to be the most memorable finale the Royal Festival Hall has ever seen.
Sadly, Fuckhead are absent tonight, which celebrates the venue's 50th birthday by gathering former Meltdown curators. In their absence, erstwhile Pere Ubu frontman David Thomas provides the evening's most startling sight, his notable girth squeezed behind a red plastic apron. Thomas's voice remains as bizarre as his appearance, jumping from whisper to deafening bleat mid-phrase. While Pere Ubu's wit was darkly mordant, Thomas is positively avuncular. Through a dense mesh of treated guitar and trumpet, one song appears to be a complaint against BBC weatherman Michael Fish.
Even by their own sombre standards, Nick Cave and the Bad Seeds' current album, No More Shall We Part, is a remarkably bleak affair, yet tonight Cave too is in playful mood. He chuckles and teases the audience between songs, but his set is affecting and strangely intimate. As they run through a selection of the new album's highlights, Cave's wracked voice and the restrained, stately rumble of The Bad Seeds overcomes the impersonality of the Festival Hall's 1950s interior.
But it is Elvis Costello's shambolic appearance that embodies Meltdown's appeal. Performing alone, he experiments with tape loops and drum machines, thrashes a distorted guitar, encourages singing from a startled audience, plays an aged and heartbreaking American folk song and encores with an unsettling reading of his 1986 track I Want You. "I haven't a clue what I'm doing," he says, smiling, to appreciative applause. Freed from the standard conventions of a rock gig, he's clearly having the time of his life.