Sentimental musical melodrama set among the colourful inhabitants of the Parisian demi-monde. It's make-believe, but René Clair creates such a rich atmosphere with the wonderful studio sets, costumes and expressionist lighting that it's how we come to imagine Paris between the wars, courtesy of the nostalgia of cinema.
A street singer (Albert Préjean) seeks romance with a penniless immigrant (Pola Illéry) but fate conspires against him. The triangle is completed by Edmond Gréville, who film buffs will know as a director of B features in UK after WWII. There's a lot of underworld malarky with a gangster and a pickpocket, which facilitates a highly stylised portrayal of life on the streets.
Clair became a success in Hollywood, usually making ambient pictures like this. There is a peculiar impression of the talkie era arriving during production. It fluctuates between sound and silent approaches. The soundtrack is mainly for songs, including the guileless singalong waltz of the title, naturally played on accordion.
The director's use of crane shots is prominent, and his mastery of montage. The camera sweeps us from the rooftops of Paris and down to the gutter. For the poor, life is sorrowful and unjust and love is the only glimpse of happiness. The audience is positioned as tourists in their world. It's very slight, but an unusual vignette lifted from the big parade.