<Tr> <Th> Based on </Th> <Td> Tristan by Gottfried von Strassburg </Td> </Tr> <Tr> <Th> Premiere </Th> <Td> 10 June 1865 (1865 - 06 - 10) Königliches Hof - und Nationaltheater, Munich </Td> </Tr> <P> Tristan und Isolde (Tristan and Isolde, or Tristan and Isolda, or Tristran and Ysolt) is an opera, or music drama, in three acts by Richard Wagner to a German libretto by the composer, based largely on the romance by Gottfried von Strassburg . It was composed between 1857 and 1859 and premiered at the Königliches Hof - und Nationaltheater in Munich on 10 June 1865 with Hans von Bülow conducting . Wagner referred to the work not as an opera, but called it "eine Handlung" (literally a drama, a plot or an action), which was the equivalent of the term used by the Spanish playwright Calderón for his dramas . </P> <P> Wagner's composition of Tristan und Isolde was inspired by the philosophy of Arthur Schopenhauer (particularly The World as Will and Representation), as well as by Wagner's affair with Mathilde Wesendonck . Widely acknowledged as one of the peaks of the operatic repertoire, Tristan was notable for Wagner's unprecedented use of chromaticism, tonal ambiguity, orchestral colour and harmonic suspension . </P>

Who wrote the words to wagner's opera tristan und isolde