John Ernest Cook (11 October 1918 – 12 August 1984) was an Anglo-American organist, composer and church musician.
John Cook was born at Maldon, Essex on 11 October 1918. After leaving St. John's School, Leatherhead, he entered Christ's College, Cambridge as an organ scholar where he came under the influence of Hugh Allen and Boris Ord. A conscientious objector to the second World War, he left his Cambridge studies prematurely to drive an ambulance during the Blitz of London.
Following the War, Cook spent three years at The Old Vic Theatre in London as an assistant to Herbert Menges. He also worked as a copyist for Ralph Vaughan Williams on the score of the 1948 film Scott of the Antarctic and with Benjamin Britten on his chamber opera Albert Herring.
In 1949 Cook was appointed as Organist and Choirmaster at Church of the Holy Trinity, Stratford-upon-Avon where he served for five years before accepting a similar post at St. Paul's Cathedral in London, Ontario. It was during this time that he joined the teaching faculty of the University of Western Ontario and commenced his nine-year association with the Stratford Festival as resident conductor and composer.
Cook left Ontario in 1962 to claim the coveted post of Organist and Choirmaster at Church of the Advent in Boston—a landmark Episcopal church in the Anglo-Catholic tradition. Having established himself as a gifted organist, conductor and composer, he joined the faculties of the Longy School of Music in Cambridge and the Massachusetts Institute of Technology (MIT).