RADIOHEAD frontman Thom Yorke famously sang No Surprises on the band’s bestselling album OK Computer.

But volunteers at Oxfam’s bookshop in St Giles felt distinctly shocked when they found a book of Blake’s poetry annotated by the rock legend and on sale for 50p.

The book had been donated by Yorke and contained an early draft of the song Airbag, the opening track on the 1997 record.

Andrew Chapman, a rare books specialist at the shop, was alerted to the find and immediately realised the donation’s potential worth.

The 48-year-old, a volunteer at the store for the past 16 years, said: “I’m a big Radiohead fan, and another volunteer, Alex Barker, was flicking through the poetry books on sale and came over and said ‘look at this’.

“I immediately realised the book shouldn’t have been put out for 50p and took it off the shelf.

“The book is a tatty Penguin 1960s paperback of Songs of Innocence and Experience, but Yorke’s lyrics and the annotations make it very special.

“It’s amazing to think this song on OK Computer was inspired by the poetry of William Blake – this could well be the first draft of Airbag.”

Father-of-one Mr Chapman wrote to Yorke to alert him to the sale and told him that he lived next door to drummer Phil Selway in Headington Hill when OK Computer was released.

He added: “I let him know the book could be sold at auction and he contacted head office to say that would be fine.

“Thom came into the store about eight months ago with a few books to donate and this was one of them.

“One of the volunteers priced it at 50p and put it out but fortunately the mistake was spotted and it is due to be sold at auction in London – it could raise at least £1,200 for Oxfam.

“The Syria refugee crisis is one of our main priorities at the moment and this money could help provide tents, water and clothing for families who desperately need it.”

The singer’s lyrics are penned on the inside cover, with other notes throughout the poems.

Mr Chapman added: “OK Computer is a great album. I remember seeing the band at Glastonbury in 1997 when they headlined and the heavens opened.”

It’s not the first time the books expert has stepped in to earn Oxfam a small fortune. In 2008 he picked out a scruffy copy of Rumour at Nightfall, Graham Greene’s third novel, which raised £15,000.

The Blake book is due to be auctioned in London on Friday, March 18, but no guide price has yet been revealed.