Yeasayer, ICA, London<field name="starRating">fourstar</field>

Yeasayer are a Brooklyn-based band wowing critics and crowds on both sides of the pond. Their main rivals are Columbia graduates Vampire Weekend. The two bands share a postcode and a fondness for African pop music, but there the similarities end. Vampire Weekend are self-consciously preppy and East Coast-intellectual, their lyrics referencing obscure grammatical disputes and high-class holiday destinations. Yeasayer are too dressed-down to be self-consciously anything.

Their set opens with a wash of cymbals and samples, which coalesce into the pseudo-Eastern guitar riff of "Worms, Waves", from their debut album All Hour Cymbals. Much is made of Yeasayer's love of world music, but their three-way vocal harmonies, the Woodstock hair of guitarist Anand Wilder, and bassist Ira Tuton's David Crosby 'tache are pure West Coast rock. It's an odd pose for a band from Baltimore (via New York), but it seems to work.

The new single "Wait for the Summer" is full of tambourines and handclaps, its exhortation, "Someone help me please!" one of the evening's few distinguishable lyrics. "2080", their best-known tune, comes in a noisier, more urgent spirit than on the album. Singer Chris Keating prepares his looped samples and sequences with the precision of a superstar DJ, but his band is more about soundscapes than detail, with waves of warm, semi-organised noise rolling over the loping, sweaty percussion.

"Waiting for the Wintertime" has a foreboding bass-line but, like "No Need to Worry", becomes a bit of a drone, both tracks indicative of a second-half lull. Keating injects some energy by battering a misshapen crash cymbal with his maraca. The album's hidden track may as well be called "Mary's House" (one of the other audible lyrics). It begins with an intriguing mixture of real and synthesised drum sounds and ends with a brilliant guitar break and an optimistic vocal refrain.

Yeasayer's support act, fellow Brooklyn-ites Dragons of Zynth, join the headliners on stage to bang whatever comes to hand for a jubilant rendition of their final song, "Sunrise" – the album's gospel-tinged opener. The performance climaxes in an exultant clatter of percussion, after which both bands hug each other like football teams at the end of an exhausting friendly.

Yeasayer's is a manifesto for facing a bleak future with festivity, instead of fear. To judge by this show, it's a programme they're following to the letter.

Also playing at the ICA tonight (020-7930 3647)