I'm not going to show off, but I can cry out of one eye. Constantly. It's a talent I acquired at circus school when I was younger, before all the hullabaloo about poor working conditions and charges of exploitation. Anyway, it seems that some pop stars out there can cry on demand too, and they all seem to be doing it while a camera points in their direction.

First up is dear old Mariah Carey. The video for her new single 'Bye Bye' is an emotive piece of cinema verite, a distillation of what it's like to live the life of a mega-selling pop diva, but have real feelings too. Over plaintive keys and a subdued beat our heroine jots down some tender verse (or is a shopping list?) and wipes away a tear that starts to...hang on, you can't see a tear, there's no sign of moisture, for all we know she could be wiping a crusty bit of sleep from the corner of her eye. But no, the music and lyrics are there to anchor the meaning, she is crying she just cries very differently to how you or I do it. The best (or worst) bit of this video is the juxtaposition between the images, the way the clip of her crying marries up with the shot of her descending the steps of her private jet, or the way the words "I never knew I could hurt like this" play over a shot of her in a bikini. It's postmodern genius, a kind of diamond-encrusted self-help video.

Next up is everyone's favourite retro-soul-diva, Duffy! You love her, I love her, your mum loves her, what's not to love? Some may say she's souless, dull and completely disingenuous but what do they know? Go and listen to Adele you losers! Anywho, here Duffy is showing Mariah how it's done. No barely seen tears here, we're talking full on panda eyes, tears streaming down the cheeks and no mistake. I love the way she totally breaks down the 'fourth wall', the way she pleads with the director to stop filming because she's crying so damn much. But the evil director just tells her to shut it and keep singing (probably). It's just a shame that it's all so unconvincing...and boring...and very very serious. Give me Mariah in a perfectly lit room in a five star hotel being really upset any day of the week (except Tuesdays when I'm at pilates).