Lily Allen, Somerset House, London

We're smiling in the rain with Lily

Lily Allen's gig at Somerset House was a distinctly British affair, with a sodden crowd dancing in the rain to her hit "LDN", the lyrics of which speak of the capital in sunnier climes. There were ponchos, umbrellas and rainhoods galore but the abysmal weather did little to dampen the spirits.

Allen was energetic, warm and enthusiastic, if a little self-depreciating with her insistent apologies for smoking. Brits like popstars with vices though and since she stopped binge drinking and slimmed down to pin-up popstrel proportions, it's good to know Lil's still as down to earth as she ever was. She rattled through an extensive and accessible set, her shoop-shoop choruses and hooks giving even the part-time fans ample opportunity to join in, and bounded around the stage with a confidence and exuberance that was wonderful to watch.

Too often decried as another saccharine and insubstantial female vocalist, Lily Allen is the exception rather than the rule, with a pitch-perfect voice that is happy at both girlishly high octaves and at the low drawl of her mockney sing-speak, not to mention intelligent, witty and aphoristic lyrics, which remain easily decipherable even during a live show. The package makes for a happy audience, waiting to join in with their favourite riffs and the lines that make them laugh. Her fans also seem to take pleasure in the dichotomy between that sweet little voice and some of filth it spouts, as on "Fuck You", a sing-song anti-homophobic totem against George W Bush that the crowd reacted to as if it were "Kum Ba Yah".

Allen included much from her second album It's Not Me, It's You, which was released earlier this year. It's an understandable decision, given it's over three years since her debut, but a slightly disappointing one, because it was that first record that people so loved her for, and its content was sharper, more inventive and less trite. Where her recent songs are full of social observations and some political ones, 2006's Alright, Still is an odyssey of London nightlife and youth culture, which is funnier and somehow less pretentious. Still, her audience were only to happy to sing along to what they knew, and Allen was conscientious in covering all of the numbers that the average pop-picker might recognise – her Mark Ronson-produced cover of the Kaiser Chiefs' "Oh My God", for instance, and her first hit "Smile", which the audience sang right back to her. Allen was in her element, flitting with ease between stately acoustic-jazz standards and frenetic, tongue-twisting tracks, whipping up an electronic storm with her reverb box and synths.

But there was a diffidence in her set towards its close. After a bassline-inspired remix of "The Fear", she tinkered with drum-and-bass effects, before segueing into a cover of Britney Spears' "Womanizer". This sort of novelty extra is fine for crowds at festivals who may not be familiar with an artist's back catalogue, but when you're playing to a crowd of your own fans, you don't need things like this; besides which, Allen has more than enough songs in her repertoire to keep an audience happy, most of which of which are better and more musically complex than any of Britney's.

Allen dedicated her last number, recent hit "It's Not Fair" (which tells the tale of a thoughtful boyfriend who is terrible in the sack), to the ladies in the crowd and, to their glee, reprised the chorus several times over. The arrangement was ingenious, spanning country and western to Nineties euphoric house, and showing that, not only does Lily Allen know her musical bread and butter, she is able to transcend genre, audience and generations. That, and the timeless vagaries of the female orgasm.