The Voice

For an insight into the day job of the BBC Director-General two years into his role, I pop into Tony Hall's plate-glass eyrie at New Broadcasting House. I arrive in the aftermath of one of the regular encyclicals that DGs dispense.

He's sung the praises of the BBC's place in a "thriving, free and competitive market", an alternative to what a colleague terms the "Joni Mitchell" school of heartstring-tugging about the Beeb's innate brilliance.

After winning hearts as a judge on BBC One's The Voice, Rita Ora has jumped ship to its competitor, X Factor. The ITV show has also poached famous BBC face – or rather voice – Nick Grimshaw, who hosts the prestigious Radio 1 Breakfast slot. While Grimmy will fulfill his judging duties alongside his BBC role, Ora's may come as a blow to BBC producers. But this isn't the first time stars have jumped ship. Here are a few of the most famous and most surprising moves.

1. Susanna Reid