Wagner revolutionised opera by merging music, drama, poetry, and visual spectacle into a unified Gesamtkunstwerk (total artwork). His Ring Cycle — four operas based on Norse mythology — took 26 years and required a custom theatre at Bayreuth built to his specifications. His use of leitmotifs and radical harmonic language pointed directly toward the 20th century. His fierce antisemitism and later appropriation by the Nazis make him one of history's most contested cultural figures.

• Nationality: DE
• Roles: composer