I don’t want this to become a “thing” on this blog — this isn’t really the place for this discussion — but I want to explain myself further in case I was unclear or confusing before.
When I took music lessons, I was told that works of music without words are referred to as “pieces” and not songs. Mozart and Bach wrote pieces and they wrote songs. Sometimes I think they have been adapted from songs to pieces or vice versa. Of course, everyone has different opinions and definitions. For us, while filling that ask meme, we defined a song as something sung, usually by a character. We also did try to acknowledge the other music in the movie, especially if it was something we felt strongly about.