"Der Rosenkavalier" is an opera composed by Richard Strauss with a libretto by Hugo von Hofmannsthal. Premiering in 1911, it is set in Vienna during the 18th century and tells the story of a love triangle involving Octavian, a young nobleman, Marie Therese, an older woman, and Baron Ochs, a comical suitor. The opera explores themes of love, aging, and social class. The work is known for its lush orchestration and beautiful melodies, particularly the famous trio in the final act. It combines elements of comedy and drama, showcasing the complexities of relationships. "Der Rosenkavalier" remains a staple in the operatic repertoire, celebrated for its rich character development and emotional depth.