Boasting such inspiring titles as Tractor Drivers, Vacation on the Black Sea, The Plow that Broke the Plains, and Our Daily Bread, state-sponsored, ideologically correct musicals were the biggest form of film entertainment going in the post-World War II Eastern Bloc. Stalin's favorite was a little gem called Volga Village, which he reportedly had watched hundreds of times and gave as a gift to visiting foreign dignitaries.
It's not as weird as you think. There was always something a little hokey about Soviet Communism. Think Youth Pioneer Leagues and Communal Calisthenetics Groups. Russians have always had an idealistic soft side, and the total betrayal of that idealism by pretty much every authority figure ever to exist in Russia ever probably has a lot to do with why they drink so much.
But, hey if chorus lines of overalled workers singing about five-year production quotas sounds amusing to you, and you don't mind watching and laughing at one of the greatest collective tragedies of the 20th century (and I certainly don't), check out the excellent recent documentary on Soviet Musicals, East Side Story.