Devendra Banhart, Koko, London

"Alternative-folk", "freak-folk", even "psych-folk" are expressions that have been used to describe the Texan-born singer Devendra Banhart and his band The Grogs. But at Koko, it became clear that the group, part of the New Weird America movement, has morphed into a very different beast from the quirky, folky hippies who produced Cripple Crow in 2005.

Banhart bounded onstage like an excitable puppy, launching into "Make it Easier" from the group's 2002 album Oh Me Oh My... It was upbeat, energetic and thoroughly camp. Banhart has clearly nicked his New Romantic style from Roxy Music's Bryan Ferry and added a pinch of Prince for good measure. But in very tight jeans and trendy yellow smoking-jacket, he could have been fronting a middle-of-the-road indie band of several denominations.

Gone is the band's signature twanging of acoustic guitar and Venezuelan influences. In its place are heavy electric riffs, loud drums, and, slightly comically, a tambourine and the occasional maraca, played by Paul Butler, currently on loan from The Bees. The band looked and sounded slick. They blasted out "Baby" from Banhart's newest album, What Will We Be, with panache. Banhart stood on one leg and shook the other violently to the music as he scatted in playful enjoyment. The crammed-in and sweating crowd strained forward, demanding more.

Banhart returned to the acoustic for a few songs mid-set, charming his audience with a husky rendition of "Little Yellow Spider". The Grogs temporarily become a barbershop quartet, before performing a rollicking version of "Foolin'". But quite suddenly the gig segued into a confusing mix of jazz, indie, blues, rock and funk. At one point, Banhart inexplicably invited a member of the audience to perform a song. He then said "I'm going to make a lot of shitty, shitty jokes," before doing just that.

What started out as an interesting and well-structured performance descended into the ridiculous – guitar solos increased exponentially, the dancing became more erratic, the loud whoops reached a higher pitch, and, excruciatingly, a cover of Taylor Dane's "Tell it to My Heart" was dedicated to Banhart's mother. It was silly, it was invigorating, it was entertaining. It definitely wasn't folk. But the audience drank it up greedily.