Tarantino films are a good example of the soundtrack being important. And the popular songs that appear in that soundtrack. It would be good to finally get a way to say “this song appeared on this film’s soundtrack”.
Thanks for reminding me of that thread 
: Classical works, "part of", and Fantasia The confusion some of us non-classical editors hit is part of the problems here I think. A language barrier of terms.
https://musicbrainz.org/release/3414d6a5-48ae-48bb-ad2e-461b0ed6afa5