Based on this Russia Beyond article:
5 Soviet musicals that stole Hollywood’s limelight
www.rbth.com/arts/328920-soviet-musicals-movies/amp
I added all the films that I could find from this second article:
10 Soviet musical films the whole country sang along to
www.gw2ru.com/arts/1631-soviet-musical-films
Two I couldn't find on Letterboxd are
Higher than Rainbow (1980) is probably the same film as Over the Rainbow (1986)
Sorcerers (1982) is listed as Magicians (1982) in Letterboxd and TMDB.