Here's my favorite example of a pop song (though arguably second-tier in actual popularity) from the early 90s that, in my opinion, had some sophistication in the music, if not the lyrics: "That's What Love is For" by Amy Grant: https://www.youtube.com/watch?v=lPOe8VKqgJM Observe the way it moves between keys, the chord progressions in the chorus, and the way the guitar solo leads into a key change. Contrast that with so many later pop songs that are just a repeating four-chord pattern all the way through. I mean, there have been four-chord songs for decades (there's that famous Axis of Awesome video), but the classic four-chord songs usually didn't repeat those four chords through the whole song.