A bump on the head costs the Stones £5m

The 62-year-old guitarist's recovery over the next few weeks, following an operation to relieve pressure within his skull after falling out of a tree, means up to six shows could be pulled from the start of the European tour until he is fit enough to rejoin the band.

The Stones' team is still negotiating how to reschedule the tour and fit in the axed shows, which should have kicked off in Barcelona a week on Saturday.

An industry insider said: "The Stones can make up to £1m per show. Obviously the tours are a real money-spinner, so they will be very keen to make sure they can keep the losses to a minimum."

The band's 2003 dates gave them the year's highest-grossing tour, taking $300m from 116 shows.

Richards fell from a coconut tree while holidaying in Fiji last month. He was taken to Auckland, New Zealand, where he underwent surgery on Monday, which a spokesman said was "100 per cent successful", to ease pressure after he complained of headaches.

He has checked out of Auckland's Ascot Hospital and is spending some time recuperating.

Inside Keef's brain: An exploration by John Walsh

On Wednesday, a tabloid newspaper told its readers how a blood clot was causing Keith Richards's brain to swell against his skull, and explained the process with the help of a cross-section cranial diagram. It didn't help much. What fans of the rock'n'roll vampire really need is a map of his brain after four decades of excess, a lifetime of tours, booze, groupies and more mood-altering chemicals than are stored in the warehouses of GlaxoSmithKline. What's it like to be inside Keith's ravaged, bandanna-ed cerebrum?

You can imagine a lot of brain energy devoted to the acquiring of the same sustenance and stimulants - the daily diet of shepherd's pie (it's the only thing he eats on tour), the Marlboros, the Jack Daniel's. You can intuit that whole sections of tissue are mildewed with toxic abuse. But don't be too certain. For years interviewers were told: don't bother him with questions about the 1970s and 1980s. Waste of time - he remembers nothing. It's not true. Woe betide the hack who got a date, a gig, a detail wrong about the Stones' back catalogue.

Keith has a few hundred songs washing around somewhere in his frontal lobes - maybe only the opening chords in some cases, but that's where his skill as the world's most exciting rhythm guitar player is best deployed. Locked in his head are the 12-bar Delta blues that first vamped him when he was a teenager - Howlin' Wolf and Muddy Waters, and the unique sound of Elvis's guitarist Scotty Moore, that Keith could never quite replicate.

Along with the music, we can infer, is the foggy memory of a few thousand undifferentiated gigs - same view of the chaotically demented first 20 rows, same view of Michael Jagger's back, same duets with Ronnie Wood. But if would be odd if among them, two didn't rank high: the concerts at the Station Hotel Richmond in 1962-63 when the Stones were having their extended eureka moment, discovering how rock'n'roll could transform audiences, generations, eras; and the welcome-home concert at Brixton Academy at the end of their 1995 world tour, a gig at which half the posers in London pretended to have been present.

With his 60s has come a wheezy family sentimentality: he dotes on his daughters Theodora and Alexandra ("Little T and A") by the model Patti Hansen with whom he lives in Connecticut, and on his son Marlon, who disobligingly made him a grandfather in 1996.

And over in the memory corner, right at the front of the vast queue of songs and girlfriends, will be a large aide-memoire: "Coconuts. Don't climb the trees, man. Just buy a Bounty."