I started reading “Information” by James Gleick this week. In the first chapter he talks about how the African drums were used to convey messages at a distance. The interesting thing about this was that the sounds played by the drummers are more like spoken language, rather than code (like Morse code for example).
African languages depend a lot on pitch of the syllables, and the drums – by using two different pitches – could send the “pitch shape” of the word. To resolve any ambiguities transmissions were augmented by additional rhyming phrases that allowed the receiver to understand. The idea is similar to saying “Victor” for “V” in radio transmissions.
An Englishman, named John F. Carrington studied the drum languages for many years and wrote a book about it “Talking Drums of Africa”. I will have to look this book up at some point.