Op. 13 is a 2-manual organ of 29 stops placed in a rebuilt and extended rear gallery of the elegant 1872 Carpenter Gothic sanctuary. The organ is entirely encased in painted solid poplar casework. Its shape and decorative elements pick up architectural elements from the sanctuary. The decorative pipe shades of mahogany were carved by Martin Pasi. The case assumes the vital tonal function of blending and focusing the sound of the pipes, while also protecting them from dust.

The new console and bench are made of cherry, with walnut highlights. The manual natural keys are covered with cow bone, the pedal naturals are maple, the sharps for the manuals are ebony and those for the pedals are rosewood. The stop knobs are arranged in terraces to either side of the keyboards. The stop knobs and toe pistons are Pau Ferro.

The organ is laid out horizontally in order to preserve a view of the large rear window. Therefore the pipes of the Great and Pedal divisions are placed on windchests divided on either side of the Swell, which is slightly lower in the center of the case. The Swell pipes are enclosed behind expression shutters, rather like large Venetian blinds, just behind the case (façade) pipes. The two largest pedal stops, the Subbass and Posaune, stand on a separate chest at the lower rear of the organ.

The key action is entirely mechanical, the organist's fingers directly opening the valves beneath the pipes through a system of levers and thin wood connections called trackers. This ancient system gives the organist intimate control over the speech and release characteristics of the pipes, for a sensitive control of musical phrasing and articulation, and through careful design and construction promises longevity measured in centuries. The console is detached from the organ case, allowing the choir to see the organist clearly. In a tour de force of careful design and construction, Martin Pasi has created a suspended key action, in which the keys are hinged at the rear and literally hang from the valves, or pallets, in the wind chests, equal in lightness and responsiveness to the finest actions in organs with attached consoles.

The stop action is electric, a solid-state combination action with eight levels of memory providing for recall of numerous stop combinations. This state-of-the-art technology allows the player maximum flexibility in controlling the many tonal colors of the instrument./p>

The organ draws its principal tonal inspiration from the great North German organs of the 17th and 18th centuries, leavening its resources with several stops inspired by 19th and 20th century models. This enhances its flexibility in choral accompaniment and interpreting 19th century and later solo organ literature. Enclosing the pipes of the Swell division behind expression shutters affords the organist a more subtle range of dynamic control.

The four major families of organ tone, principal, flute, string and reed, are all well represented in the new organ. The principals are the foundation stops of any fine organ, a sound unique to the pipe organ. Choruses of these stops are present on both manuals and pedal. The presence of three façade Principals at the unison pitch (8-foot) is very unusual for an organ of this size. The tonal essence of the organ springs from the intense and vocal quality of these pipes, with their clear, articulate speech under sensitive control of the mechanical key action. On the Great and Swell full choruses of principals (octave, quinte, sesquialtera, mixture, scharf), representing the higher harmonics of the sound, are built above these façade pipes.

Flutes are represented in many forms and pitches (Bourdon, Spitzflöte, Rohrflöte, Nasard, Gemshorn, Tierce, Gedackt), the names reflecting both the shape of the pipes (stopped, tapered, stopped with chimneys) and their tonal function. On the Great the family of flutes at the first five pitches of the natural harmonic series form a bold and yet sweet cornet registration.

The Viola and its companion Celeste provide colorful string sound useful in choral accompaniment and Romantic organ literature.

The organ’s reed stops are quite varied, from the strong Trumpet and Posaune (Trombone), to the sweeter Oboe and Dulcian, an ancient form of clarinet. All but the Oboe are inspired by stops in the baroque organs of North Germany, especially those built by Arp Schnitger, who worked in the Hamburg area from about 1670-1720. The full and yet focused sounds of the Trumpet and Posaune are particularly representative of Schnitger's work. The piquant Oboe is modeled after 19th-century stops by the French master builder, Aristide Cavaillé-Coll. An unusual addition to the organ's tonal palette is the Chamade, a trumpet stop beginning at Middle C on the Great, its pipes placed horizontally at the front of the case in a manner pioneered by Spanish baroque builders. It has a bright and commanding solo voice from this position.

All of the pipes, metal and wood, flue and reed, were made in the Pasi shop, from the casting of the metal through to the completed pipes. The metal pipes are made of 98% lead, with trace impurities of copper, bismuth and antimony, which help stiffen the metal. To enhance the intensity of the pipes’ sound, the metal is hammered following casting, which tightens its molecular structure. The Subbass and the lowest 12 pipes of the Great Bourdon are made of poplar, the only wood pipes in the organ.

The organ is tuned in the Kellner/Bach unequal temperament, which favors the keys nearer c major, and yet remains harmonious through all keys.

An electric centrifugal blower supplies wind to the organ, which is stored and regulated in a single wedge-shaped bellows measuring 4 feet by 6 feet. The bellows and blower are located in the bell tower. This wind system imparts a gentle flexibility to the organ’s sound, allowing the pipes to sound more like a choir of human voices than an impassive machine.

Two special stops frequently found in Baroque organs lend a festive air to the organ. The Zimbelstern (Bell Star) has eight small bells struck in a repeating sequence. The gilded star above the center façade pipe turns when the stop is drawn. The Vogelgesang (Bird Song) is a single pipe placed upside down with its end submerged in a cup of water. It makes the sound of a chirping bird when drawn.

-Mark Brombaugh