Radiohead/The Big Ask Live, Koko, London

Friends are first to hear new sounds from Radiohead

Never ones to let the unexpected pass them by, two members of Radiohead unveiled songs from their new album with an acoustic set.

It was a Friends of the Earth benefit for 1,000 fans at a former dancehall in Camden.

Though they have long striven to distance themselves from the histrionics that made them global stars, recent albums have relied on electronic effects to create a disembodied sound. Hail To The Thief in 2003 was characterised more by resentful moods than for unforgettable anthems. Its follow-up has already been vaunted as a change of direction now the band have cut ties with not only their label, but also longstanding producer Nigel Godrich.

Moreover, here were the ringleaders of the Radiohead awkward squad. Singer Thom Yorke has always been uncomfortable with his profile, preferring to scowl at his audience and subvert proceedings. Classically trained Jonny Greenwood has been even more diffident, though able to express himself via some of the most powerful guitar sounds of his generation.

A curt "how are you?" from Yorke was his only welcome, though "Karma Police" needed no introduction, even with the frontman on guitar and Greenwood's beanpole frame hunched over an upright piano. The audience were soon in full voice. It was an instant reminder that despite all the sonic trickery Radiohead were first and foremost songwriters of distinction.

Yorke's muscled banter between songs was lost to us up in the gods, but it was clear he was a proficient busker, hitting a taut rhythm on "There, There" to which his partner added a crunchy accompaniment on his electric guitar.

Then Yorke finger picked precisely first newie "Arpeggi". As well as carrying a beautiful melody, he sang his most plaintive tune since "OK Computer". It was a straightforward arrangement, but no less beguiling for that. Another new tune had Yorke sample his voice to devise a rhythm, Laurie Anderson style. Like its peers it was propelled by a direct beat with an insistent tune on top. On the more proggy "Fake Plastic Trees" the pair met the crescendo to its emphatic chorus before the wearied finale. Greenwood even betrayed a sense of humour by peppering the number with seagull cries to add his own brand of subversion. Yorke, meanwhile, half-read green messages from small notes before chucking them away for the simple slogan, "It's not too late".

Such flashes of wit were welcome given his strained demeanour. Yorke was as serious as can be while performing. Koko was a large venue for a duo to cover, but his intense delivery made it all the more intimate. It was a night made for the lullaby charms of "No Surprises", played with immaculate grace.

Yorke had his turn at the piano, while Greenwood towered over him. The guitarist also played pedal steel and keyboard to produce a variety of odd atmospherics. Some of the more introspective songs could not be pepped up, though, to be lapped up anyway by their dedicated fans.

In the encore came another tuneless ditty that would have earned them few pennies at the Tube station. It made the epic "Paranoid Android" an unlikely closer. A brave choice they carried off with aplomb.