The art of transcribing orchestral accompaniments for organ is one of the most difficult problems which organists must face. Although a few will become professional recitalists, most organists will at one time or other have a church position and be required to play oratorios and other large choral compositions which were originally scored for orchestra. Several of the most popular of these works (Handel's Messiah, Saint-Saëns's Christmas Oratorio, Fauŕe's Requiem) have already been arranged for organ, but the majority are available only in piano reductions. The main body of the paper deals with this latter group of works, for it is here that the most urgent problems exist. However, some of the organ arrangements now available need considerable revision because they try to imitate the whole orchestra and are virtually impossible to play. Therefore, some preliminary comments on already existing transcriptions seem necessary.