If I write about “popular music” in this manual, then I usually mean the music that was born in the 1950s, although per definition this is not really correct of course.
In this book I’ll discuss the music that started with rock ’n’ roll, which was basically a combination of African-American genres (such as blues, jazz, or gospel music) and Western swing and country music.
Which also means that today’s music itself didn’t come out of nowhere, it originally was nothing but an unusual combination of ideas that existed before. What made it so revolutionary back then was the mashup of black and white art, at a time when both cultures were still strangers on many levels.