"Love is Blue" by Paul Mauriat was number one on the Billboard pop chart 50 years ago today. Mauriat was a French conductor and orchestra leader.
His instrumental version is actually a cover of a song written by Andre Popp with lyrics by Pierre Cour for the Eurovision Song Contest.
In that contest each participating country enters a song which is performed during a live television broadcast. This was Luxenbourg's entry in 1967. They enlisted Greek singer Vicky Leandros to sing it with the original French lyrics. She finished fourth in that year's contest.