Watch Orlando Furioso: Vivaldi: San Francisco Opera (1990) : Full Movie Online Free Antonio Vivaldi's opera is set on the enchanted island of the sorceress Alcina. Although old and ugly, Alcina can make herself appear beautiful to bewitch courtiers who set foot in her realm. When fate brings Angelica; her lover, Medoro; and the jealous Orlando to the island, Alcina finds herself challenged. American mezzo-soprano Marilyn Horne heads a stellar cast in this San Francisco Opera production.