The Mysteries Remain With an organ composition there is always the dilemma as to how specific to be concerning registration. Since the composer conceived this work with a definite organ and building in mind, it was felt that more specific suggestions of registration would be of value. However, it should be emphasized that this composition may be successfully played on organs varying greatly in tonal concept.The organ at Saint Mary’s Abbey (Morristown, New Jersey) is a nineteen stop unenclosed instrument, bright in sound and patterned after baroque instruments in Northern Germany. It is housed in a large building with three seconds of reverberation. Though registration will vary greatly from organ to organ (and a larger instrument with an enclosed division might provide certain advantages) the organ part should always be assertive and colorful in character. The trumpet and organ parts are conceived as equal.