Wilhelm Richard Wagner (22 May 1813, Leipzig, Germany - 13 February 1883, Venice, Italy) was a German composer, conductor, music theorist, and essayist, primarily known for his operas (or "music dramas" as they were later called). Unlike most other great opera composers, Wagner always wrote the scenario and libretto for his works himself.

Wagner's compositions, particularly those of his later period, are notable for their contrapuntal texture, rich chromaticism, harmonies and orchestration, and elaborate use of leitmotifs: musical themes associated with specific characters, locales, or plot elements. Wagner pioneered advances in musical language, such as extreme chromaticism and quickly shifting tonal centres, which greatly influenced the development of European classical music.

He transformed musical thought through his idea of Gesamtkunstwerk ("total artwork"), the synthesis of all the poetic, visual, musical and dramatic arts, epitomized by his monumental four-opera cycle Der Ring des Nibelungen (1876). Wagner even went so far as to build his own opera house to try to stage these works as he had imagined them.

Source: Wapedia