I thought he’d be remebered here, if only for being a guest star on The Muppet Show.
More seriously, he was probably the last of the great chanson singers that came to the fore in the '50s and '60s and that included Jacques Brel, Georges Brassens, Barbara, Léo Ferré, Jean Ferrat, Serge Reggiani and arguably, Serge Gainsbourg, right before rock, and English pop in general, changed the French musical landscape.
He wrote dozens of songs that are now part of the standard chanson repertoire, with La Bohème probably the best-loved one. Coincidentally, I started practicing a piano solo version of it this Summer. Bummer.