became Hahn's best-known concert work. Tagliaferro and Hahn later recorded the work for the gramophone; the recording has been reissued on CD. In 1931 Hahn wrote the music for the opérette Brummell. In 1933 he became Le Figaro'''s music critic. In the same year, Ciboulette was filmed for the cinema. The young director Claude Autant-Lara made a fairly free adaptation of the stage work, with Simone Berriau in the title role; it opened in Paris in November 1933, and was well received. Hahn's only major commission for the Paris Opéra was the work based on The Merchant of Venice that he had begun composing during the war. Le marchand de Venise, with a verse libretto by Miguel Zamacoïs, premiered in March 1935. It was received with enthusiasm, and although it was not revived in Paris during Hahn's lifetime it had several new productions later. Guitry and Hahn worked together on another show, O mon bel inconnu (O My Beautiful Stranger, 1933), starring Arletty. The reviewer in Lyrica commented "Is it operetta? No; comic opera? Not that, either; vaudeville? Not in the least. So what is it? I don't know, but it is unpretentious and it is charming". He added, "Neither of the two authors, so admirably gifted, gave the best of themselves, but the crumbs they nonchalantly let fall from their table are still enough to compose a nice meal". Hahn composed the music for two other musical comedies during the 1930s as well as a considerable quantity of incidental music for plays and films. In the second half of the decade Hahn was again prominent as a conductor, directing performances of The Magic Flute, The Seraglio and The Marriage of Figaro. His fidelity to Mozart was remarked on in the press: after years of productions at the Opéra-Comique in which the composer's recitatives in Figaro were replaced by spoken dialogue, Hahn used a new, more scholarly text edited by Adolphe Boschot. In the concert hall he formed musical partnerships with younger performers; in addition to Tagliafero, he regularly accompanied Ferrant and the soprano Ninon Vallin. When the Germans occupied Paris in 1940, Hahn left for the south of France and then for neutral Monaco. He was less at risk there from Nazi anti-Semitic persecution, but narrowly avoided being killed by the explosion of a stray shell from a British submarine aimed at a German warship moored near his rooms