The French New Wave’s great, forlorn metaphysician Alain Resnais has not seen his stock rise in his dotage; art film meteors like Hiroshima Mon Amour and Last Year at Marienbad have not worn nearly as well as Godard’s or Truffaut’s first films, and his last movie to find decent release in this country was 1986’s Mélo. All the same and all this time, Resnais has been one of the global scene’s few true explorers, once fascinated by cinema’s potential for ambiguous signification, and lately more quizzical about the nature of its pleasure. It’s to Resnais’s credit that his work has gotten more buoyant as he’s aged, and 2003’s Not on the Lips is as helium-filled as any film by an octogenarian. Adapted from a larky and surprisingly witty 1925 operetta (last filmed in 1931), the movie is a sure-footed, tongue-in-cheek theatricality—except that it’s vitally cinematic, with a feel for spatial relations and a respect for real-time performance that should make the Oscar winners for Chicago want to save face via seppuku. The plot is paradigmatic musical-comedy crossed-swords romantic nonsense, with an expert cast (Lambert Wilson, Sabine Azéma, Audrey Tautou, Isabelle Nanty, et al.) spending nearly as much time conversing with us as crooning to each other. But Resnais’s real subject is almost 80 years of sound-movie rapture, with as many props offered to Rouben Mamoulian’s Love Me Tonight as, movingly, to Resnais’s late Left Bank colleague Jacques Demy, for whom no human trial was too sad for song. Additionals are limited to a trailer and a still gallery.