The Great War was also the scene of what historians consider the first genocide in history, a sort of rehearsal for the Nazi extermination programme in World War II, namely the systematic and deliberate destruction of the Armenian population by the Ottoman Empire, who had entered WWI on the side of Germany. The number of victims is generally estimated at over 1,200,000. As a result, many Armenian artists joined the diaspora, bearing worldwide witness to the fertile heritage of their ancient culture: from Charles Aznavour to Cathy Berberian to the American metal band System of a Down, who devoted several songs to the Armenian genocide. Liana Ghazaryan is a young Armenian opera singer whose extraordinary voice has not forgotten her roots.