I don’t think there really is a ‘definition’ of pop, certainly not from a genre perspective. There are certain qualities that pop broadly adheres to- short, tonally up-beat, simple, catchy choruses and transitions. Not all pop songs exhibit every convention, but some mixture of those elements will be present in any given pop song. The name itself comes from the original explosion of top-40 radio in the 50’s, which was dominated by doo wop and early rock n’ roll, the first truly nationwide popular music trends, but I don’t think it’s been directly correlated with commercial viability since the 60’s, and plenty of pure pop gold has fallen by the wayside, like this-
The Ramones were pop AF. Their whole thing was in reaction to noodley over-jammed Led Zep et al. Doo-wop on speed was the result. Blondie explicitly aimed to be pop stars, and freely stole from any genre to get there- Chris Stein is a criminally overlooked guitar mutant, possessed of ridiculous flexibility, could play anything. More Songs About Buildings and Food and Fear of Music are perfect examples of anti-pop/art-pop, the intentionally difficult colliding with a familiar form.
Little Red Corvette, that’s about as perfect of a pop song as you get IMO.
Rivers Cuomo is a pop fetishist! Nerded out so hard he mathematically broke down his favorite songwriters so he could devise an equation for writing infinite pop songs.
And Bowie was all over the place, a product of his thoughts on evolution and progression.
I think what it boils down to for me is that pop is more about qualities of a song than necessarily a description of an artist. I dunno. It’s all subjective anyway, ain’t it?
