Bit late in this thread - sorry.

My mother ran a French restaurant in Kensington in the 50s-60s, with piano & accordion & live singers. The customers most liked hearing sort of folkie well-known songs -

Aupres de Ma Blonde
Chevaliers de la Table Ronde
Jeanneton Prend sa Fourcille
L'Alouette
Savez-Vous Planter Les Choux?

Some pop standards by the likes of Trenet

La Mer
Boum
Valentine
Je Cherches Fortune Autour du Chat Noir

......

~M~