Union of Soviet Composers
According to the official credits, all the music is by Isaak Dunayevsky Lyubov Orlova had been sistematically trained as a pianist from 1907 to 1922 (with 3 courses at the Moscow Conservatory), and, from 1920 to 1926, she worked professionally as a musician. In 1961, Orlova strongly implied her collaborative efforts in songwriting weren't credited, highly likely, because of the strict rules about the non-members of the Union of Soviet Composers. There is a story about a conversation between Dunaevsky (nicknamed Dunya) and Dmitry Shostakovich: