Pete Doherty, Brixton Academy, London

This London gig was rescheduled after Pete Doherty's latest drug-related jail spell. He's on his best behaviour, looking puffy or perhaps just well-fed, starting on time and finishing late, holding a raucous crowd with only an acoustic guitar (and the judicious, playful use of a violinist and two ballerinas).

The last chances he's been using up aren't just legal, though. The songwriter who, with his Libertines collaborator Carl Barat, turned a twilit English hinterland of Tony Hancock, George Orwell and The Clash into lyrics and lives which were excitedly compared to Byron, has been silent lately. Doherty acknowledges he's been "getting grief" for playing the same core of good songs for years, and that tonight he'll be filing them away, before "going away" to write. As he's found to date, it's easier said than done, the incoherence of his life leaching creativity.

Many of the songs tonight are from the Libertines albums, now almost a decade old. He hunches forward into the mic for "Can't Stand Me Now", and there are cheers for old times' sake. But the lyrics about his old severed alliance with Barat have to be gotten over, if he's to have a future beyond nostalgia for that very short if potent moment.

His self-awareness goes back to The Libertines' "What A Waster", and his defiance to Babyshambles' anthemic "Fuck Forever", with its line "happy endings are so boring." But a song he wrote for Amy Winehouse, and also dedicates to his friend Robin Whitehead who died of an overdose last year, brings home the possible cost. Doherty does a neat little impression of the unimpressed Winehouse ("Is that all ya got?"), and has a loose, committed strum through her "Tears Dry On Their Own".

There's a slight weariness tonight, the old songs played with mildly creative affection, but not driven home as if they're fresh. The contrast between the slickly professional "folk" scene led by Mumford & Sons and Doherty's scratchily affecting, never-quite-finished acoustic sketches is still profoundly in his favour. He remains absently charming, open to his audience and charismatic, and by the end really hits his stride. Even if that's another false dawn, as absent, remembered friends tonight prove, it's better than no dawn at all.