Ryan Adams, Forum, London

"I'm gonna play all night," Ryan Adams promises the crowd. "You think I'm joking? I've got a 5am plane, man..."

I would almost have taken that as a threat at the start of this marathon, see-sawing show. Claims that Adams was a rock saviour always rang hollow to me, his ability to impersonate Neil Young's blue-eyed ballads and the Stones' swagger having somehow become confused with equalling their status.

When his fourth solo album, Love is Hell, written after a bad break-up, was allegedly rejected by his label as "too dark", it seemed like he was adding to his own would-be myth, notching up a "lost" album, more than pouring out real emotional pain. Mixed reviews for the replacement record, Rock'n'Roll, and a slating for a gig earlier in the week, though, have got his juices going, and tonight he gives us everything he has.

For the first hour, that's nothing special, despite an adoring crowd's screams. Opening with a brace from Love is Hell (soon out as two EPs), he allows a pregnant pause before singing, then droops martyred on to his mic-stand, hanging his pretty head of hair, while his new band, the Killers, kick in. At first he doesn't talk, instead playing pumped-up rock while stumbling around on bandy legs borrowed from Elvises Presley and Costello, even his limbs in hock to the past. Then he mysteriously decides this "sucks", stops for a band meeting, and opts to replay the night's weakest song, the Noel Gallagher knock-off "Shallow", in ragged, a capella close harmony. Such freewheeling spontaneity seems as gauchely self-conscious as most things he does. But it opens things up for the encore, when the night catches alight.

Effectively a second, solo acoustic set, cherrypicking old songs till now ignored on tour, the crowd's roars show this is how they want him. "You sexy fuck!" a woman bellows during the delicate ballad "Oh My Sweet Carolina", summing up the female reaction to his boyishly sensitive side. Ragged screams, shushing and near-fights break out in the intimate quiet around Adams' suddenly softened, exposed performance, charging the air in a way his songs alone don't. Regular shouts of "genius!" are out of all proportion to his writing, singing or playing, but when he lies back and puffs a cigarette in near-post-coital contentment after "My Winding Wheel", crows: "Now, that's a song," after his anthem "New York, New York", and turns The Strokes' "Last Night" into an aching lullaby, his bratty, giddy self-satisfaction creates its own charismatic gravity.

He also mixes his egotism with a star's needy, unreserved love for his fans, finally wading into them, even handing his tambourine to a bouncer to play, as all the boundaries break. By the second encore it seems he may never leave, like an alt.country Al Jolson. But, near midnight, he does. Spoilt, hyped, unconvincing and unoriginal, he has still somehow sated his desires, and ours.