Comment by vintermann

Self-supplied metadata in music catalogs is notoriously shit. The degree to which most rights owners don't give a damn is telling.

Spotify's own metadata is not particularly sophisticated. "Valence", "Energy", "Danceability", etc. You can see from a mile away that these are assigned names to PCA axes which actually correspond pretty poorly to musical concepts, because whatever they analyzed isn't nicely linearly separable.