Sub-Saharan Africa West and Central Africa), or sometimes extending from the coast of West Africa to Western Sudan. Its equivalent in Southeast Africa was "Zanj" ("Country of the Blacks"), which was situated in the vicinity of the Great Lakes region. The geographers drew an explicit ethnographic distinction between the Sudan region and its analogue Zanj, from the area to their extreme east on the Red Sea coast in the Horn of Africa. In modern-day Ethiopia and Eritrea was "Al-Habash" or Abyssinia, which was inhabited by the "Habash" or Abyssinians, who were the forebears of the Habesha. In northern Somalia was "Barbara" or
German horn excessive. Although the French firm Jérôme Thibouville-Lamy in about 1928 introduced a piston-valved double-horn with ascending third valve, designed in collaboration with the horn player Louis Vuillermoz, the double horn has continued to be identified mainly as a German horn. The double horn essentially combines two instruments into a single frame: one horn in F, and a second, higher horn keyed in B. Like the single horn it has three valves, but each has a double set of tubing, the first tuned in F and a shorter set in B. By depressing a fourth valve (usually operated by the thumb),