L'accordéoniste, (music and lyrics by Michel Emer in 1940) . Edith Piaf in Wikipedia. Michel Emer also wrote J'm'en fous pas mal (a precision for those I know who like this song -as I do too-).
Just for Mex..iiiii..co! Luis Mariano is famous for this song part of the operetta created by Francis Lopez. He had previously sang in La belle de Cadix (also by Francis Lopez, lyrics by Maurice Vandair) : la belle de cadix a des yeux de velours...