Horn of Africa displays the greatest diversity, a sign often viewed to represent a geographic origin. The Horn of Africa is also the place where the haplogroup E1b1b originated from, Christopher Ehret and Shomarka Keita have suggested that the geography of the E1b1b lineage coincides with the distribution of the Afroasiatic languages. Genetic analysis done on the Afroasiatic speaking population further found that a pre-agricultural back-to-Africa migration into the Horn of Africa occurred through Egypt 23,000 years ago and it brought a non-African ancestry dubbed Ethio-Somali in the region. Together with northern Somalia, Djibouti, the Red Sea coast of Sudan and Eritrea is
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),