Some of his songs had unconventional subject matter, with whimsical imagery bordering on the surreal. "Y'a d'la joie" evokes joy through a series of disconnected images, including that of a subway car shooting out of its tunnel into the air, the Eiffel Tower crossing the street and a baker making excellent bread. The lovers engaged in a minuet in "Polka du Roi" reveal themselves at length to be "no longer human": they are made of wax and trapped in the Musée Grévin. Many of his hits from the 1930s and 1940s effectively combine the melodic and verbal nuances of French song with American swing rhythms.