Merrill’s 1944 operatic debut was in Verdi‘s Aida at Newark, New Jersey, with the famous tenor Giovanni Martinelli, then in the later stages of his long operatic career. Merrill, who had continued his vocal studies under Samuel Margolis made his debut at the Metropolitan Opera as winner of the Metropolitan Opera Auditions of the Air in 1945, as Germont inLa traviata. Also in 1945, Robert Merrill recorded a 78rpm record set with Jeanette MacDonald featuring selections from the operetta Up In Central Park; MacDonald and Merrill did two duets together on this album.
In 1951, Merrill did a series of duet recordings together with the Swedish tenor Jussi Björling, including a world-renowned recording of “Au fond du temple saint” from the opera Les pêcheurs de perles by Georges Bizet.
Again in 1952 Merrill, Björling, and Victoria de los Ángeles made a widely admired RCA Victor recording of Puccini’s La bohème, conducted by Sir Thomas Beecham. In 1953, Merrill, Björling, de los Angeles and Zinka Milanov recorded the complete Pagliacci and Cavalleria rusticana.
Robert Merrill made 769 performances with the Metropolitan Opera in the following 21 roles: