The band, who left the stage minutes ago, thrilled the 2,500-strong sell-out with brand new tracks 'Optimist', 'Morning Bell, 'Dollars And Cents', 'National Anthem', 'In Limbo', 'Everything In Its Right Place' and 'Knives Out'.

The crowd, who at times were virtually hushed in awe, gave the new songs a rapturous reception, with 'Knives Out' garnering the best reaction.

Introduced by frontman Thom Yorke as a song "about cannibalism", the track is the most radio-friendly of the new born songs and reminiscent of a darkly twisted 'Street Spirit'.

The rest of tracks were characterised by their experimental nature being composed of looser more experimental grooves - and were as dark as the band said they would be. The new songs suggest that the sound of the forthcoming album will be nothing short of magnificient as Radiohead explore their boundaries further.

The full set list was:

• 'Talk Show Host'
• 'Bones'
• 'Optimistic'
• 'Karma Police'
• 'Planet Telex'
• 'Morning Bell'
• 'Dollars And Cents'
• 'Street Spirit'
• 'National Anthem'
• 'My Iron Lung'
• 'No Surprises'
• 'Climbing Up The Walls'
• 'Lucky'
• 'In Limbo'
• 'Exit Music'
• 'Airbag'
• 'Everything In Its Right Place'

The encore consisted of:

• 'Just'
• 'Knives Out'
• 'Nice Dream'
• 'Paranoid Android'

Of the new material, 'Morning Bell' bears influences of Thom Yorke collaborator DJ Shadow with glimmers of 'Airbag' and features cut-up rhythm of syncopated beats that builds until it spirals towards the edge of control, bringing to mind Miles Davis' 'Bitches Brew'.

'National Anthem' is driven by a powerful fuzz bass that wouldn't have been out of place on Primal Scream's latest offering 'Xxtrmntr' and is topped with Thom making his very best throwing up noises, a la Elastica's 'Line Up'. It is arguably one of the more accessible of their debuted tracks.

'In Limbo' featured more syncopated, staccato guitar work from Jonny Greenwood, with a powerful loose groove to give it some meat.

After the song Thom said: "For those of you with tape recorder, that was 'In Limbo'. I wouldn't want you to get it wrong". Previously he had said, somewhat bitterly: "All the new songs will appear tomorrow on the Internet anyway."

'Everything In Its Place' meanwhile brought to mind incidental music from some '70s cop show, with Jonny sampling Thom's live voice and playing it back over and over.

At the beginning of the encore Thom, looking stylish in a white zipper jacket, took more photos of the audience, asking: "Do you want to be on our website tomorrow?"

He concluded the gig with a simple "Thanks for being so nice to us on our first gig back" and the band simply filed offstage after final track 'Paranoid Android'.

Tony Acer, a fan who'd travelled to the gig from London told nme.com afterwards: "The new songs all sound fantastic, but they're pieces of music rather than songs, just these amazing grooves that just transport you. It was such a fantastic gig."

Nick from Virginia, USA said: "'Exit Music' was the best song of the night but 'Knives Out' is as good as anything they've done. I've heard some of the new songs before on Napster but they were amazing live. I'm looking forward to seeing them again in Florence." Paul, a fan from Arles said:"They're evolving. The new album's going to be amazing."