George Shirley sang ten Met performances with Anna — in Faust, La Traviata, Manon, Die Zauberflöte and Roméo et Juliette. In 1972, the tenor was at the Met for Mozart’s Ottavio and Tamino, but was corraled into service as Roméo, opposite Anna, when the scheduled tenor, Franco Corelli, did not show up for rehearsals or for the first performance.