African music as found in the western half of the continent has an overall shape despite major distinctions from north to south. This music came to the New World via the slave trade and then spread to Europe and further to the rest of the world. While European music and the ping-pong effect of African-derived music in the New World coming back to Africa have affected the music greatly, the essence of the music remains strong and continue to spread to the rest of the world.
African music is made up of short repetitive units combined and recombined from various instruments and voices into a kaleidoscope. Westerners have frequently heard only the kaleidoscopic effect and copied that to great effect, but those imitations lose the richness of the multiple units that create the tapestry of sound.
In order to hold together multiple units played on multiple instruments by multiple players combining with multiple voices, a time line is employed. Where Western orchestras require a conductor or master to direct, Africans rely on the time line, classically expressed with a bell or sticks (cowbell or clave), or sometimes only held in the head.
About one hundred of these time lines have been charted, only a few of which are employed by any one musical culture. The son rhythm came to North America to form the basic rhythm of rock and roll, the push-pull base for the jitter bug and other swing dances. Another is dubbed “shave-and-a-haircut– two-bits” and is the classic rhythm of the popular music we call salsa. More time lines can be found in the Americas in the many traditions of Afro-American music.
Just as we would not consider music Western without chords, we cannot consider music African without the cross-rhythmic heart of the music. While Westerners, confronted with what appears to them as a bewildering welter of rhythms, give up and decide Africans just have some mysterious ability to turn all that into music (and many just decide it is not music at all), Africans enjoy the constant tension-resolution that occurs constantly as the rhythms cross, clash, and then resolve into a pleasurable sonic experience. But not entirely sonic; there is something else without which African music might not be possible: it is the internal rhythmic sense Gunther Schuller rendered “forward propulsive directionality.” Of all the terms and descriptions I’ve heard and read, that catches it. It is a constant propulsion forward that always has a powerful sense of direction. Without that internalized pulse, the short-hand term I prefer over ‘beat” or “rhythm”, the music lacks for the listener the emotive force provided by other means in other musical traditions. Yet the lack of that internalized pulse has not prevented people all over the world from loving the African-derived musical forms they hear.