I am worried by how good these sound. By good, I of course mean 'bad', but in that horrible good version of bad that gets beneath your spine and makes you smilecringe all the way through them. They are recently released pop songs, as sung by clips culled from Team Fortress 2, and they sync up in a thoroughly impressive manner. Listen to two of the best/worst after the jump.

Jump! Here you go. First up is the Scout singing Ke$ha. She's the sparkle-faced popstrel who always looks a little bit like she needs someone to scrub her with a flannel; he's the little twat with a bat.

Then the Heavy takes on Justin Bieber's 'Baby'. The song, I'm not suggesting he's due for a paternity suite.

So they'll be in your head all day, via Ed Fenning . Got any more good TF2 mashups?* Whack them below.

*I apologise for writing the word mashups.