A guide for teaching the essential musical elements of opera to undergraduate students is provided. The course centers around "The Marriage of Figaro" by Mozart. It is presented in four sections. In section I, students investigate type casting of opera singers in terms of the ranges of their voices. Students learn to differentiate coloratura, lyric, and dramatic soprano; mezzo soprano; contralto; tenor; baritone; and bass. Section II focuses on the opera conposer's musical language. Students examine musical analogies, associations, and imitations. When listening to musical scores, students are required to locate examples of operatic analogies. Written definitional assignments are also included. Section III investigates the use of ensemble in opera. The ensemble allows two or more characters to sing simultaneously, thereby expressing two or more emotions to the audience. Students identify ensembles in "The Marriage of Figaro,""La Boheme,""Madame Butterfly,""Don Giovanni,""Rigoletto," and "Amahl and the Night Visitors." In the final section students analyze musical form in opera. Balance, symmetry, and contrast through statement/counterstatement, arrival and departure, and repetition and variation are studied. A list of appropriate readings and suggested questions and activities are included in each section. (KC)