REM, the American supergroup who have managed to hang on to all their credibility for 18 years while shifting many millions of albums, will be entertaining 300 invited guests at the small Radio Theatre inside the BBC's Broadcasting House.
The show, to be broadcast live on Radio 1, will run for two hours, watched by their fan club, along with Radio 1 competition winners.
Presenter Mark Radcliffe is to interview the revered rock stars from Athens, Georgia, during the first hour of the programme, which starts at 7pm, then the band will play.
"We feel extremely privileged," a Radio 1 spokeswoman said. "We know we are very lucky to have them. In the hour before we announced the competition, we received the usual 3,000 calls, but in the following hour we received 9,000."
The enormous interest is fairly predictable given that REM have sold more than 35 million albums and rarely perform, even in the States.
"Without wanting to appear obsequious, this really is a thrill for me," Manchester-based Mark Radcliffe said. "REM have always been one of my favourite bands and when I was asked to do the programme, I had no hesitation in saying yes - even though it meant coming to London. I know Stipey [singer Michael Stipe] will appreciate the sacrifices I'm making to help his band with this, their big break."
The band are in Britain to promote their new album, Up, released tomorrow, which has won rave reviews for its musical inventiveness and emotional range. It is the first record the group have produced since their drummer, Bill Berry, who nearly died from a brain haemorrhage on the band's last tour, left to pursue a quieter life.
The band had always promised if any of its members left it would have to dissolve but, in the words of Stipe: "A three-legged dog is still a dog, it just has to run differently."
The concert tonight will be the first time a British audience has seen REM as a threesome. Bill Berry, who wrote Everybody Hurts - one of the band's biggest hits - was much more integral to the unit than most rock drummers.
If British REM fans, or "diStiples" as they are known by the music press, are jittery with excitement, it is not just down to the Radio 1 coup. The band have a tantalising reputation for giving impromptu gigs at small venues when they are abroad.
In 1990, following the release of their Out of Time album, they played in the Borderline club in London under the pseudonym of Bingo Handjob.
"It was one of the most amazing things," said south London fan Richard Craig, 28, who watched the Handjob gig. "The only problem was that a lot of my friends were so jealous that I couldn't really talk about it to them until a long time afterwards."