It was a collaboration that bemused both the rock and pop world. When Welsh rockers Kids In Glass Houses enlisted the help of one their famous female fans - Frankie Sandford of the British girl band The Saturdays - to record a duet, their pick for a vocalist in 2010 was certainly surprising. "Undercover Lover" tied with "Give Me What I Want" in the ranks of commercial but since then, it has become the 'Voldemort' of KIGH's back catalogue - the song that shall not be played.

VERDICT: Classic, but not according to the band.