Well, Mooman, of course African music existed before the word "folk" was coined. Similarly, the world existed before the word "world" was invented. But the word "folk" was created, in the 19th century as you say, precisely in order to define certain kinds of African music. Given that fact, it seems pretty perverse to say that there is no African music one can call "folk".      The old village band playing the old wedding tunes for a wedding in Moldova is folk. The old village band playing the old tunes for a wedding in Sierra Leone is folk. Ditto Outer Mongolia, ditto Paraguay. You can't write off a whole continent as having no folk music.