Chu Chin Chow was a well-known stage musical that started during the First World War years and lasted through the twenties and the thirties. Then mention of it suddenly stopped and was heard of no more. Of the songs used in the musical, only the Shoemaker's Song was catchy enough to survive outside the musical, and was covered by all kinds of musicians from trad jazz bands to Paul Robeson.
As others have said, the musical is set in Baghdad and is a variant of Ali Baba and the Forty Thieves. The costumes are exaggerated, with grotesque turbans and fezzes.
What is unusual for a British film is that the background music is almost non-stop. Often the background music has nothing to do with what is happening in the scene, and is thus more like Muzak in a supermarket or an elevator. This was sometimes done in early thirties films by First National/Warner Brothers. This is the first time I have encountered this in a British film.
The orchestration is adventurous and the higher pitches feature unusual instruments. These include domras that tremolo in the string section, and - soloing in the woodwind - are a sopranino recorder, and even an ocarina, to accentuate clownishness. As big jars, each containing a thief, are rolled into a pit, we hear the timpani making a thunderous noise - inappropriate due to the size of the jars, but unbelievably effective.
With one exception, the singers are not very good. The exception is the Australian basso profondo, Malcolm McEacharn, who is billed as "Jetsam," because he was a member of the Flotsam and Jetsam duo. An exceptionally rich and powerful voice that can reach down, down, down to depths that a basso cantate like myself can only dream about.
I have never seen anything quite like this in a British film of the period.
