"Knock Knock Who's There" by Mary Hopkin

One of the first artists - if not the first - signed to The Beatles' Apple label*, Mary Hopkin's first single, 1968's Those Were the Days, not only bumped her employers' classic Hey Jude out of the Number One spot after just two weeks it also out-performed another version of itself, by Sandie Shaw, in the same year. Her second single, Lennon and McCartney's Goodbye, was then itself held to the Number 2 spot on the UK chart in 1969 by The Beatles' Get Back.

Hopkin later represented the UK at the Eurovision Song Contest in 1970 with the spritely little ditty you see here; Knock Knock, Who's There? was selected from a field of six by a postal vote, and won by a wide margin with 120,000. She'd sung all six songs during the UK National Final, which that year was called A Song for Europe, and which aired on the television variety series It's Cliff Richard! This one - number six, in fact - proved the most popular; despite her flawless performance, though, Hopkin came second to All Kinds of Everything, performed by Irish singer Dana.

Born in Wales on this day in 1950, Mary Hopkin married Tony Visconti in 1971 (they would divorce in 1981) and thereafter withdrew from the 'scene' as such, although she continued to record and occasionally even perform despite her aversion to the limelight and reputed distaste for the music industry. She released an album, entitled Valentine, on her own label as recently as 2007.

*Paul McCartney signed her on the advice of Twiggy, who saw Hopkin perform on the televised talent show Opportunity Knocks - which was the Britain's Got Talent of its day.
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