Horn of Africa at the 2012 London Olympics. According to the IMF, in 2010 the Horn of Africa region had a total GDP (PPP) of $106.224 billion and nominal of $35.819 billion. Per capita, the GDP in 2010 was $1061 (PPP) and $358 (nominal). States of the region depend largely on a few key exports: Over 95% of cross-border trade within the region is unofficial and undocumented, carried out by pastoralists trading livestock. The unofficial trade of live cattle, camels, sheep and goats from Ethiopia sold to other countries in the Horn and the wider Eastern Africa region, including Somalia and Djibouti, generates
Natural horn for natural horn. Benjamin Britten's "Serenade for Tenor, Horn and Strings", though written for the modern horn, makes notable use of the F harmonic series and has been recorded at least once on a natural horn. György Ligeti's "Hamburg Concerto" makes a great use of the natural horn and of natural sounds on the modern horn in the solo part and requires four natural horns in the orchestra. Below lists natural horn keys with their corresponding fingering on the modern horn. If a piece of music says the key on the left you can press the key combination on the