[yesenadam]

Talking about this stuff without saying what kind of music you mean seems a little silly. There is a reference to "one popular song", and it seems the author is thinking of pop music. But it seems most things that can be said about keys/chords in one genre/tradition/style, don't apply to others. And even within genres, things naturally evolve so that old rules no longer apply.

[peterkos]

Yup! Adam Neely has a great video[0] talking about how serious of a role any theoretical framework has on understanding the music itself -- and how in the US at least, we very often prescribe European standards of harmony on music.

[0] https://www.youtube.com/watch?v=Kr3quGh7pJA&t=2s

[dizzystar]

The popular song is "Creep" by Radiohead.