In 1968, Ledger became an artistic director of the Aldeburgh Festival with Benjamin Britten and Peter Pears, often conducting at the Snape Maltings, including the opening concert after its rebuilding and first performances of works by Britten. He worked regularly with the English Chamber Orchestra during this period. He was Director of Music at King's College, Cambridge from 1974 to 1982, and conductor of the Cambridge University Musical Society from 1973 to 1982. During his Cambridge years, he directed the Choir of King's College in the Festival of Nine Lessons and Carols, made an extensive range of recordings, and took the choir to the United States, to Australia, and to Japan for the first time. Ledger then became principal of the Royal Scottish Academy of Music and Drama from 1982 to 2001.