Oberlin was one of the leading figures in the revival of early music. Despite his early retirement from singing at the age of 36, he played a vital part in reviving enthusiasm for not only the repertoire, but the countertenor voice, carrying on in the United States the revival Alfred Deller had started in England. In fact, he claimed to have been the "only true countertenor" of his period, rather than a falsettist. While mostly associated with early music, he was also a noted performer in contemporary music, particularly the role of Oberon in Britten's A Midsummer Night's Dream. Aside from reviving the voice and repertoire, he also helped redefine the expected countertenor sound by allowing vibrato and more expressiveness rather than the previous English standards of a very clean, almost preadolescent voice that sounds most natural in sacred music. Arguably, he paved the way for the more passionate performances of David Daniels, Jochen Kowalski, Derek Lee Ragin, and Brian Asawa, as well as helping create an audience for them. In his native Ohio (he was a descendant of Jean Frederic Oberlin, for whom the college, noted for its music school, is named), he performed in local choirs as a soprano, singing professionally by the time he was six. His voice first changed to a low tenor, but then rose again to tenor. In 1946, he entered Juilliard, graduating in 1951. Among his early musical jobs was an unusual stint: singing backup for Edith Piaf. Two years later, he became a founding member of New York Pro Musica, a group dedicated to reviving forgotten early music. It was while performing with Pro Musica that he "officially" changed to countertenor and began to make his mark in early music performances elsewhere. By 1959, he had so firmly established his solo career that he left Pro Musica, returning only for guest appearances. He also performed widely in the theater outside the realm of music, including the Broadway production of Lillian Hellman's adaptation of Anouilh's The Lark and the American Shakespeare Festival Theater in Connecticut. Additionally, he appeared on many of Leonard Bernstein's television music specials, created scholarly editions of Purcell's songs, and read poetry for the Lark Ascending (a New York group re-creating the feeling of musical afternoons during the times of Wharton and James.) In the mid-'60s, he began to limit his performances and concentrated on teaching, becoming professor of music at Hunter College.