I Blame Coco, Proud Galleries, London

Imagine the face of 19-year-old Coco Sumner, frontwoman of I Blame Coco and daughter of tantric soft-rock god Sting, on finding out that Courtney Love had been squeezed on to the top of the bill for tonight's show at the last minute.

As the living incarnation of rock'n'roll, Love would be an intimidating addition to any up-and-coming band's gig, but for I Blame Coco's singer, struggling to snatch success from the jaws of the ridicule levelled at her for her privileged upbringing, the challenges are manifold. There's already a mountain to climb for the girl whose six-album deal with Island records (a subsidiary of Universal, owners of The Police back catalogue) is steeped in suspicion

Still, if this pressure has bothered Sumner, it's impossible to tell from her confident and vivacious performance. New material veers between the kind of electro-tinged pop, which makes Lady Gaga's "Bad Romance" an apt, if unfortunately weak, cover, and darker, guitar-driven angst-rock which can't help but recall Avril Lavigne and even Tatu.

Whichever mode Sumner is in, her demeanour remains the same; a demure mixture of coquettish nonchalance interspersed with jerky dancing and, just once, a smile, which is reserved for the chorus of closing number "Caesar", comparatively well-received by an audience to whom the rest of the night's material is new. There's an affected dash of Santigold and MIA to her vocals, and it seems that recording the group's first serious material in sunny Jamaica may have done wonders for its unashamedly light earlier material, but it will do nothing to quell claims that Sumner's voice is too heavily influenced by that of her father.

When it comes to sidestepping the charges of nepotism, lyrically, Sumner's done herself no favours; references to Lord of the Flies and the experiments of psychologist Stanley Milgram smack of a sixth-former showing off; and that's just in "Caesar". It's a very rarefied kind of rebellion I Blame Coco present to their audience. Early demo material referred to party gatecrashers ruining her parent's "brand-new Chesterfield" sofa, as if another image of the clash between rock'n'roll and the precocity of the children of the rich and famous were necessary.

With Courtney Love a no-show and the crowd responding encouragingly to unfamiliar material, it turns out it may be I Blame Coco's evening after all. As Woody Allen said, 90 per cent of life is just showing up.