Myles, did you ever see Mr. Blanding's Dream House? The house painter scene, where the lady of the house explains, in elaborate detail the precise shades of color that she wants for each room ('sort of a robin's egg blue, with a hint of sunlight at dawn' for the bath', etc.) and after she goes through the whole schtick for each room in the house, as I remember it, the painter turns to his assistant and says: "Ok, bathroom: blue, kitchen, yellow, etc."
Contemporary music since the dawn of R & R is simpler and louder, right?
If I were to elaborate beyond that :go backwards- pop music in the form of big band, maybe some early modern jazz, certainly blues with the roots of R & R (not sure how much that crossed over racial lines then), ragtime, 'band' music, what else? (Leave classical out of it, it was probably a pretty small segment, even in the early 20th century).
Probably a fair amount of diversity, compared to what is truly big selling mainstream today, I don't know.