Description:

A little mouse that can't sleep insists on changing babysitters until he finds one he likes. Based on the poem by Samuil Marshak, featuring the music of Dmitriy Shostakovich.

The original children's poem by Samuil Marshak was written in 1923, and has become one of his most popular works (the original Russian text can be read here).

Tsehanovskiy had the idea for adapting this story with Shostakovich doing the music in October 1934, while he was still working on his "Balda" animated feature (which remained unfinished and was mostly destroyed in WW2). At the end of the 1930s, he wrote a script together with Marshak which made a number of changes from the original - fewer animals, in a different order, and a happy ending was added with the mouse actually being saved. Shostakovich wrote the music in early spring 1939 - he submitted the piano score to the studio on March 26, and likely finished the full score in April. The Lenfilm studio originally only wanted to limit the orchestra to 16 performers, but Shostakovich insisted on 40 and they eventually relented. The music was recorded at the end of April or beginning of May, 1939.

The film's production lasted 18 months (one report claims that it was really 30 months; Anon 1941a) and went over budget by more than 200,000 rubles. As a result, Tsehanovskiy
was threatened by Ivan Bolshakov (President of the Committee for Cinematic Affairs) with never working again (Borodin 2005, 231).

The final film was completed in 1940, and the art council of Lenfilm made the decision to release it on Sept. 13, 1940.

The original musical score is published in the Shostakovich "New Collected Works", vol. 126. Interestingly, there are some differences between the score and what is in the final film. For example, some of the lyrics were changed (see Russian subtitle description for details). Probably the most important difference is that the scene from 11:48-12:01 (where the tension that had been building suddenly dissipates, and the cat strangely goes back to sweet singing despite nobody else watching) was not in the score - instead, the film originally jumped from 11:48 (with the mouse in the cat's mouth) straight to 12:02, with the dog breaking down the cat's door (sections 57-58 in the score, pp. 348-349).

References:
Shostakovich "New Collected Works", vol. 126. pp.379-380, 285-357.
Philip Cavendish (2021) ‘Superior to Disney’: colour animation at Lenfilm, 1936-41, Studies in Russian and Soviet Cinema, 15:1, 60
Anon. 1941a. “Ne povtoriat′ oshibok proshlogo.” Kadr, 4 January, 1.
Borodin, Georgii, ed. 2005. “Istoriia ‘nekhrestomatiinoi kartiny’: ‘Skazka o glupom myshonke’ M. M. Tsekhanovskogo v dokumentakh.” Kinovedcheskie zapiski 73: 216–237.