[Written on the back of Pupil C's hand - I hate Katy Perry]
Pupil C: Do you know who Katy Perry is sir?
Me: Not personally.
Pupil C: No...
Me: ...because she's a popular music singer, who's sung about kissing girls and boys who can't make up their minds.
Pupil C: Um... Yes.
If only they'd asked me about a band I could have used the phrase Popular Beat Combo.