I listen to probably a majority of communist songs though I really like Lyubeh (related to the soviet union but not communist), IU, Gfriend, TWICE, (don’t fucking judge me) miscellaneous klezmer bands, recently teresa teng, as well as various video game osts. (persona 4. yokai watch, etc.)
Black flag is generally leftist, with a lot anarchist themes. I mean, their name is black flag lol