Wagner (1813-1883)was a remarkable innovator both in harmony and in the structure of his work, creating his own version of the Gesamtkunstwerk, dramatic compositions in which the arts were brought together into a single unity.
As a man he was prepared to sacrifice his family and friends in the cause of his own music, and was unfortunately overtly anti-semitic.
In the later part of his career Wagner enjoyed the support of King Ludwig II of Bavaria and was finally able to establish his own theatre and festival at the Bavarian town of Bayreuth.
He developed the use of the Leitmotiv (leading motif) as a principle of musical unity, his dramatic musical structure depending on the interweaving of melodies or fragments of melody associated with characters, incidents or ideas in the drama. His Prelude to the love tragedy Tristan und Isolde led to a new world of harmony.