In 1981 Charles Fisk designed the specification for what he called "a three-manual organ appearing on two manuals." His innovative idea was to play both the Brustpositiv and the Swell from the upper manual. Reversible pedals control the wind to both of these divisions, making it possible to select either the Brustpositiv or the Swell, or to play both simultaneously. Since the Great, played from the lower manual, is essentially a constant through all periods of organ building, the ability of the second manual to take on the character of a 17th century German Brustpositiv or a 19th century French Swell gives the organ a versatility not hitherto possible on a two-manual organ. A similar specification was used at Opus 94 in Dayton, Ohio.

Just as the stoplist and pipe scaling of the organ at St. John's were designed to fit the church acoustically, the organ case was specifically designed to harmonize visually with its setting, incorporating many themes and details of the room. The outline of the case was inspired by the trapezoidal shape of the roof, details of the pipe shades use the angles and color of the church's structural work, while the design of the balcony rail¬ing is reflected in the meeting of the façade posts and their supporting im¬post. Opus 93 combines a clean contemporary style with a traditional arrange¬ment of towers and flats to produce a modern case with historical allusions.