J Mascis | Camden Underworld, London

Mascis, the man who smuggled the guitar solo back into American underground rock with Dinosaur Jnr, shuffles onto stage looking like an absent-minded Woodstock commune leader. His curtain of hair grey now and his gut round, he peers at us quizzically through spectacles before sitting on a rural back-porch wooden chair to strum an acoustic guitar. Did Kurt Cobain, you can't help but wonder, die for this?

Mascis, the man who smuggled the guitar solo back into American underground rock with Dinosaur Jnr, shuffles onto stage looking like an absent-minded Woodstock commune leader. His curtain of hair grey now and his gut round, he peers at us quizzically through spectacles before sitting on a rural back-porch wooden chair to strum an acoustic guitar. Did Kurt Cobain, you can't help but wonder, die for this?

Actually, to anyone who saw Dinosaur Jnr's on-stage immolation in 1997, when the band turned in on themselves to play purgatorial slabs of electric guitar, with their careful blend of pensive pop melody and noise exhaustedly broken and Mascis clearly past caring, the format is something of a relief. It holds out the hope of actually hearing the brighter, tighter songs on his solo debut, More Light.

Mascis, though, in wry, almost chatty mood for someone whose public appearances have in the past famously shrouded him in inarticulacy, hasn't entirely left his old ways behind. Politely plucking hillbilly acoustic rhythms on the new song "Same Day", he suddenly pulls a high, quick squall of electricity from somewhere inside his guitar's innocent-looking frame, then drops back into acoustic mode again, as amused, relieved cheers break out.

It's a schizoid moment that will come to define this performance. Each song starts quietly, allowing the intimate inspection of subject-matter of any singer-songwriter's gig, making the themes of Mascis's career very clear: the tired struggle to care, to force himself from his bed and his weary self-loathing.

The new songs are a little more optimistic. However, this veteran American punk clearly wouldn't have the energy to reach for a gun like his pupil Cobain; it's a world-view seemingly born more of ME than social disaffection.

This mood is then ritually ignored in almost every case, in favour of screaming guitar solos, extremely varied in texture, but entirely disconnected from what's gone before. It's like a collage of every discredited type of Seventies gig, from folk to Heavy Metal.

Certainly, the changes Mascis rings from his guitar are impressive: rumbling, bass-heavy darkness on "Does the Kiss Fit" and mighty, clean chords on Dinosaur Jnr's "Get Me". But it's only in flashes that he really pulls the parts of this performance together: the rasped, committed vocal on the new single "Where'd you go" is one, as are the lyrical passages of funny and detailed self-flagellation.

He doesn't play "Freak Scene", Dinosaur Jnr's beautiful anthem for the slacker-punk generation that he once represented. He does sing, pointedly, "I've got no advice about anything". And, when he mumbles "I'll be back with a band soon" it gets the night's biggest cheer.