Wild Beasts, Koko, London

It wasn't supposed to be this way. Wild Beasts were never supposed to get so big. Or that's what they thought, anyway. This is a band whose recent single, "Hooting and Howling" includes the line "A crude art, a bovver boot ballet – equally elegant and ugly/ I was as thrilled as I was appalled, courting him in fisticuffing waltz". With a lead singer whose voice has always divided opinion and whose imaginative, poetic and sometimes downright absurd lyrics make them easy targets for mockery, it seemed ridiculous to think they could become a mainstream indie fixture.

But that is exactly what has happened. In fact, Hayden Thorpe, lead singer and owner of one of the most distinctive singing voices since Antony Hegarty, even stops the set halfway through to tell the assembled crowd the story that when Koko booked them to play a show, the boys thought they'd be playing to a half-empty room, considering the Camden venue's 1,500 person capacity. It ended up selling so well that they booked another date, tonight, for the end of their UK tour. Looking at the packed out room Thorpe chuckles, "Now I'm thinking maybe we should have booked a third."

Having released their debut album Limbo, Panto to quiet acclaim in 2008, the quartet from the Lake District got their break with last year's follow-up, Two Dancers. Things were toned down slightly, the band grew into their sound, people swooned. They finished the year on most critics' "best of" lists.

The stirring intro of "The Fun Powder Plot" begins tonight's set, which is comprised equally of songs from both albums. As with many of their tracks, the sound is slowly built up and added to, layer by layer. The final instrument to be included is Thorpe's romantic falsetto, a voice that has the ability to sound like it's from another era. By the time they get to "All the King's Men", the band have really hit their stride. On this, as with a few other tracks, vocals are shared with bassist Tom Fleming, who in his chunky-knit cardigan looks like anything but a rock star. The contrast between Fleming's and Thorpe's voices is one of the real treats the band has to offer.

"Two Dancers" and "We Still Got theTaste Dancin' on Our Tongues" are perhaps the best moments of the night, during which the beats and guitars urgently build before haunting vocals come crashing over. By this point in the set, Thorpe and Fleming have lost it, with their limbs in spasm, flailing around.

At times their music can get a bit repetitive. Wild Beasts might not sound like anyone else, but occasionally they can sound a little too much like themselves. Anyhow, there are enough big moments and flourishes to ensure no one gets bored and they do well to put the dance-floor glory of "Brave Bulging Buoyant Clairvoyants" alongside the choral charm of "Please, Sir".

It is a triumphant set and the band leave the stage looking like they can't believe their good fortune. It's just like Thorpe told us earlier: "Imagine having one of the best nights of your life and then being able to do it again two weeks later." And who could possibly begrudge them that?