We know it's not Friday now, obviously. But presumably it was Friday when Katy Perry sang this song. Just watch the video, everything will be explained.

Conveniently, there’s a useable story about all Top 3 of our 100 Sexiest Women today. That’s a bit magic that is; almost like God, or Buddha, or Superman or whoever it is calling the shots up there has mystically shifted the world to give us something vaguely relevant to write about.

Just in case you've forgotten what she looks like, here's a picture of Katy Perry

Well, alright, the Rihanna story is “Rihanna looks hot shopping for stuff,” but we can work with that, yeah? So Katy Perry, officially your #2 Sexiest Woman in the World, is a singer. This you know. She sings all sorts of things, including a cover of that insidious little Rebecca Black’s song Friday, as you can see above.

Friday’s garnered a lot of derivative work ever since US funnyman Daniel Tosh featured it on his show and the video went massively viral (pretty soon the YouTube “times watched” counter will actually fill up and roll back to zero). For instance, we’ve already told you about a cheery Russian fellow who was so happy that it was Friday, he did a little dance.

There’s also this Death Metal version, which is great if you like buckets of distorted noise and shouting:

Or there’s “Bob Dylan’s” version (note - not actually Bob Dylan), which gives the song a sort of melancholic air. This sort of proves that anything sounds profound if you sing it in Bob Dylan’s voice:

Or, probably best of all, legendary political commentator and comedian Stephen Colbert sings it live on Jimmy Fallon’s show with The Roots backing them up. It’s inspiring stuff:

If you’ve got time after all those, you really should set aside four minutes to watch Alanis Morissette’s cover of My Humps by the Black Eyed Peas. It’s tremendously poignant: