Five. Four. Three. Two. One…’

As the studio clock ticked down and the black pixelated screen filled with red indicating time to press play on Jay-Z’s Public Service Announcement, her first record as the new host of the biggest gig of her life, Tiffany Calver turned and ran.

“I went into the corner like, ‘No, no no! I don’t want to do it.’ I burst out crying, because I knew, ‘As soon as I do this, it’s official’.” Calver’s emotions ...