Thom Yorke has revealed he wrote around 40 versions of hit track Paranoid Android.
The Radiohead front man penned dozens of slightly different lyrics for the OK Computer lead single, which is celebrating its 20th anniversary this year.
Yorke told BBC 6 Music's Matt Everitt about recently rediscovering his notebooks from the time the album was being conceived and "making friends with whoever this nutter was".
He said: "I was obsessive about taking notes, that was the only way to feel I was making progress.
"(I would) endlessly do different versions of the lyrics ... there are 30 or 40 versions of Paranoid Android.
"I'd just change five words", he said, adding he would be scribbling down different lyrics as he sat on the bus.
Yorke hinted the band, which will headline Glastonbury later this month, would come back together to create new music once he had finished "everything else I'm doing".
He said: "I think once that's finished there will be a collection of ideas which will give us the chance to get together.
"That's kind of how it works because the truth is we're not living on a bus together. So the way we find connection with each other is through something that has been created or half-created.
"I just want it to carry on being a process that everyone enjoys, that's all I care about, and something that is still a surprise, that's all I care about," he added.
The interview, First Time With Thom Yorke, can be heard in full at www.bbc.co.uk/6music from this Sunday, ahead of its Glastonbury weekend broadcast on 6 Music on June 25, from 1 to 2pm.