The Organ Task Force of Riverside Presbyterian Church proposes changes to the organ in order to further the mission of Riverside Presbyterian Church.

1. Proposed Organ
Restoration
February 2015

2. Organ Components
Pipework!
Sound producing portions of the instrument!
Pipes built in different sizes, shapes, and materials to achieve different tonal goals!
Voiced (adjusted to speak evenly)!
Windchest System!
Delivers air to the toe of the pipe to allow it to begin to speak!
Organ uses an electro-pneumatic system to function!
(cont.)

3. Organ Components
Winding System!
Provides stable air at a higher ambient pressure to
allow pipes and chests to operate properly!
Components include the blower, a system of
reservoirs, and a conveyance system normally made of
galvanized iron, wood or PVC lines!
(cont.)

4. Organ Components
Electrical System!
Primary function - Translate the movement of the
keys and stops into electrical impulses that will
activate appropriate switching and relay controls to
produce sounds!
(cont.)

5. Organ Components
Electrical System!
Secondary function - Combination system allows
organist to reset combinations of sounds, called
registrations, and recall them with the press of a single
button!
Also provides for a Musical Instrument Digital
Interface (MIDI), commonly used as a “data filer”
allowing the record/playback function of the organ

6. Organ Components
Console!
The control interface contains keyboards, pedalboard,
and stop controls which transfer the mechanical
motions of the musician into musical presentation.!
The American Guild of Organists has set up standard
design specifications so that the musician can easily
move from one instrument to the other.

7. Organ Specifications
The Riverside Presbyterian Church organ has (5)
divisions!
Four of which are controlled from a separate keyboard
or pedalboard!
Each division has different tonal “stops” and is
generally used for a different purpose

8. Great Division
Has the Foundation stops which are the heartiest
sounds, and which are used for hymn singing!
Frequently stops from the other divisions are
“coupled” (added to) the Great

9. Swell Division
Solo stops - “colors” of the organ, such as the flutes,
strings, and reeds!
“Under expression”, i.e. has shutters that can be opened
or shut to provide louder or softer tone!
Often coupled to Great Division for increased variety of
color and sound!
Accompanies solo registrations on other manuals, or as
an alternate softer registration when accompanying choir

10. Choir Division
Has softer stops than the Swell and the Great!
Used for accompaniment and background sound, such
as during communion!
Can act as a secondary Great and functions well in
accompanying choir singers!
Often coupled to the other divisions, and is under
expression

11. Antiphonal Division
The Antiphonal organ is located apart from the main
instrument at the rear of the sanctuary at Riverside!
Accompanies and supports congregation!
Helps fill the room with sound!
Provides softer ethereal sounds

12. Pedal Division
Played with the feet!
Not as many notes as other divisions, but about (2.5)
octaves and looks like a keyboard with larger keys!
Provides the bass notes, sounding an octave or two lower
than the other keyboards!
Some of the sounds are “borrowed” from the stops on the
keyboards, and some are specifically for the Pedal division

13. History of the Organ
Components
Console -!
Built and installed (1927)!
Replaced with low quality consoles (1962, 1973, 1999)!
Blower!
Installed (1927)!
Replaced (1973)!
(Cont.)

14. History of the Organ
Components
Swell and Choir Shutters (expression shades)!
Installed (1927)!
Rebuilt (1973)!
Wind Chests!
Two Swell chests built (1927); rebuilt (1973)!
One Choir chest built (1927); rebuilt (1973)!
One Choir chest added (1999)!
Two Great chests built (1927); rebuilt (1973)

15. History of the Organ
Components
Offset Pedal and Manual Chests!
Mixture of 1927 and rebuilding in 1973!
Wind Trunks and Lines!
Mixture of 1927 and 1973!
Reservoirs!
Mixture of 1927 and 1973

16. History of the Organ
Components
Organ Pipes!
Comprised mostly of 1927 vintage!
Great division pipework dates from 1973!
Four ranks added to the Choir and the Swell in 1999!
Antiphonal division added in 1973 and Echo division
was removed

17. Sanctuary Acoustics
The configuration of the sanctuary and the hard surfaces
on the walls and ceiling make possible the excellent
acoustics found in European cathedrals.!
At Riverside, however, the transmission of musical
sound is significantly impeded at the source by the
direction the organ and the choir face and by the baffle
created by the arch overhead.

18. Sanctuary Acoustics
Sound travels in straight lines. Thus, the organ speaks
crossways across the front of the nave, as does the choir.!
This results in the congregation receiving
minimal benefit of the music produced and the
organist/choir director not hearing the sound
delivered.

19. Sound Directional
Diagrams
Diagram A: Current!
Sound lines we currently
experience

20. Sound Directional
Diagrams
Diagram B: Better!
Possible improved sound
lines if the two Great
Division chambers were
moved from the side to the
front wall and the other
chambers were able to move
forward into the vacated
space

21. Sound Directional
Diagrams
Diagram C: Best!
Additional sound lines that
would be achieved if the
organ chambers were opened
on the archway wall into the
sanctuary

22. Sound Directional
Diagrams
Important Note: Such changes do not necessarily increase the
volume, but instead increase the richness of the sound. In
many cases, this results in a lower volume level.

23. Major Repairs Required
Most of the mechanical elements are at the end of
their useful life. Emergency repairs are temporary,
interruptive, and costly. As they become more frequent,
the organ will become me less available for services.!
Shutters (shades)!
No longer operating and must be replaced!
(cont.)

24. Major Repairs Required
Wind Chests!
A majority of the wind chests are 87 years old and
are mechanically unreliable.!
Winging Systems!
Reservoirs which resemble bellows need replacement.
An integral element is leather which is now 41 years
old and has reached the end of its reliability.

25. Major Repairs Required
Blower!
It is aging, noisy, and of limited capacity. It has a weak bearing
predicting failure sometime soon.!
Console!
Very poor quality, needs to be replaced!
Replacement (1999) was with a used unit not intended for this kind
of instrument!
Not a candidate for rebuilding and does not meet AGO specifications

26. Major Repairs Required
Pipe Chambers!
Interior is extremely crowded due to the design of
two levels of ranks within the chambers. The result is
the inability to make basic repairs without
substantially dismantling the chamber.!
Double decking leads to tuning instability, leaves
critical parts inaccessible, and is considered a safety
hazard for technicians.

27. Repairs to the Antiphonal
Organ
Consists of (2) chambers mounted on the rear of the
sanctuary above the balcony, installed in the early ’70s!
The design is such that the chambers are virtually
inaccessible for service. Maintenance and repairs have
essentially been ignored since the original installation.!
The cabinetry, resembling Danish modern, bears no
relevance to the elegant woodworking in the rest of the
sanctuary.

28. Project Scope
Pipes!
Many of the pipes are original from 1927 and
show effects of aging
Some pipes will be used from the existing instrument!
Tonal deficiencies will be addressed with the addition
of new pipework to fill the void in the tonal spectrum

29. Project Scope
Pipe Chambers!
Create two new chambers for the Great division on the front
wall of the nave!
Swell division would be under expression on the South side!
Choir division would be under expression on the North side!
Pedal division would be on the North side in its own space!
This reconfiguration would eliminate the need to double deck
wind chests

30. Project Scope
Chamber Facade!
Remove the grill cloth, which collects dirt, and replace with
speaking and non-speaking pipes!
Shutters on Chambers!
Replace all!
Console!
Secure an entirely new console meeting American Guild of
Organists standards

31. Project Scope
Replace!
Wind Chests!
Winding system including reservoirs and wind lines!
Blow and motor!
MIDI!
Antiphonal Organ!
Redesign and rearrange the rear chambers

32. Cost
The Organ Task Force has been meeting the entire year.!
Lois Gurney, Al Harding, Barbara Zacheis, Alan Ragan,
Sherrick Gilbert, Carl Zacheis (Chair)!
We retained a consultant and secured proposals (after visits to
RPC), from four organ builders.!
Two proposals were eliminated.!
Instruments built by the two remaining contestants were
visited by the committee.

33. Cost
The committee has determined that R.A. Colby, Inc.
of Johnson City, TN is best qualified to provide the
needs of RPC:!
! ! ! !
! ! !
Colby base proposal $1,239,364
Colby antiphonal organ $140,674
Openings in Nave Walls (RPC) $50,000
Consultant (Parkyn) $15,000
Total $1,445,038

34. Stained Glass Windows
The Property & Maintenance Committee has requested that I
bring young attention to the maintenance of the sanctuary
windows.!
Proper maintenance of the windows by re-caulking and replacing
the lexan covering every 25 years is due now. This maintenance
step avoids having to remove the entire windows for re-glazing.
We had to remove and replace 25 years years ago at at cost of
close to $200,000 since regular maintenance had not been
performed.!
COST: $75,000

35. Other Acoustical Matters
For the organist to hear the sound that is being
produced, consideration should be given to a better
location for the console.!
Placing console on castors with a lengthy extension card
or multiple plug ins provides maximum location
flexibility.!
Another factor is the projection of voices which is best
achieved by having the choir face the congregation.

36. Other Acoustical Matters
Chancel refurbishment and redesign may be something
the church wishes to pursue.!
The committee did not examine these matters to any
extent since they were not included in the original
assignment. Thus, no costs are provided.

37. Artist’s Rendering