Adele has announced that she is headlining the Saturday night of this year’s Glastonbury festival. She told the crowd at her gig at the O2 arena in London on Friday night that she was the third and final headliner for the festival, joining the previously announced Coldplay and Muse.

Adele’s headline slot had been strongly rumoured, even though she has shied away from headlining festivals. The Glastonbury team had been wooing her for some time, and she was taken on to the Pyramid stage before last year’s headline show by Kanye West to see the kind of crowd she might expect to play for.

It’s a measure of Adele’s power – by some distance the bestselling artist in the world right now – that she was able to break the news of her headlining slot this way. Although other headliners have made their own announcements previously – Coldplay broke the news via their Twitter account – none have done so from the stage at a gig before. The announcement of the final headliner had been expected to come next month, rather than on a Friday night in March.