Richard Strauss' fifth Opera, and arguably his most famous and successful. After the very modern Salome and Elektra, Strauss and librettist Hugo von Hoffmannsthal went with a more genteel work, one set in Vienna of the 18th century. Besides the Mozartean setting, two of the main characters could have stepped right out of The Marriage of Figaro: Maria Theresa (the Marschallin) and Octavian.