I've long heard rumors about this but was able to track down.
Often times PVA crossing the Yalu River in 1950 is depicted as in board daylight with band playing March of the People's Volunteer Army. We now know the crossing happened largely at night to avoid detection and bombing by UN forces, and it turns out the music thing is historically inaccurate too:
CCTV managed to track down a conductor who was part of Liaodong Military District at the time and was at the crossing point for a month. According to him, PVA entered Korea with such speed that March of the People's Volunteer Army was still in the process of being written, as such they played whatever music they knew like Military Anthem of the People's Liberation Army, March of the Cavalrymen and Soviet military music. And when asked if he could remember any of the tunes the conductor immediately went for Farewell of Slavianka, he apparently didn't know what the song was called back then.
Often times PVA crossing the Yalu River in 1950 is depicted as in board daylight with band playing March of the People's Volunteer Army. We now know the crossing happened largely at night to avoid detection and bombing by UN forces, and it turns out the music thing is historically inaccurate too:
CCTV managed to track down a conductor who was part of Liaodong Military District at the time and was at the crossing point for a month. According to him, PVA entered Korea with such speed that March of the People's Volunteer Army was still in the process of being written, as such they played whatever music they knew like Military Anthem of the People's Liberation Army, March of the Cavalrymen and Soviet military music. And when asked if he could remember any of the tunes the conductor immediately went for Farewell of Slavianka, he apparently didn't know what the song was called back then.