Raymond Souplex (1901 - 1972) was a much loved French comedian, actor and singer of the mid twentieth century. As far as I can make out, he was famous for:
I got hold of the song ‘T’as l’Dérailleur’ (which may translate as ‘You got the derailleur’) on a cringingly tacky CD set called ‘Les Trésors de la Radio (1930 - 1950)’ - but it is also, inevitably, available on iTunes - where you can listen to 90 seconds for free.
It appears to be a paean to the riders of the Tour de France who are urged to whole-heatedly climb the Tourmalet, Aubisque etc. using their trusty Simplex derailleurs. Users of the competing Huret or Campagnolo derailleurs of the time do not seem to benefit from Raymond’s melodic encouragement - so I suspect that a thick brown envelope may have changed hands.
Fortunately my French is so bad that this is all that I can grasp. But don’t let that discourage you from purchasing the track and laboriously translating the lyrics into English. I would then be proud to offer to share them on this site. Crowd-sourcing - it’s the very essence of the web.