The 1864 William A. Johnson Opus 161, Piru Community United Methodist Church Piru, California, Part 1: A virtually complete documentation and tonal analysis derived from the data, drawings, and photographs from the restoration of 1976 by Michael McNeil a

August 1, 2018

Michael McNeil has designed, constructed, and researched pipe organs since 1973. He was also a research engineer in the disk drive industry with 27 patents. He has authored four hardbound books, among them The Sound of Pipe Organs, several e-publications, and many journal articles.


Good documentation of organs with enough pipe measurements to permit an analysis of both scaling and voicing is extremely rare. Pipe diameters, mouth widths, and mouth heights (cutups) may be sometimes found, but toe diameters and especially flueway depths are rare. Rarer still are wind system data, allowing a full analysis of wind flow and wind dynamics, parameters that have an enormous impact on the sound of an organ. The reader will find all of this in the following essay on William A. Johnson’s Opus 161.

Good documentation is important for several reasons. We can make useful comparisons with other organs to learn how a specific sound is achieved. And perhaps most importantly, we can document the organ for posterity; while organs are consumed in wars and fires, they are most often replaced or modified with the changing tastes of time. They never survive restorations without changes. Comprehensive documentation may also serve to deter future interventions that intend to “modernize” an organ. Lastly, future restorations of important organs will be more historically accurate if they are based on good documentation.

The mid-nineteenth-century scaling and voicing of William A. Johnson is very similar to the late-eighteenth-century work of the English organbuilder Samuel Green, as evidenced by the data from Johnson’s Opus 16 and Opus 161. Stephen Bicknell provides us with detailed descriptions of Green’s work.1 Johnson’s scaling is utterly unlike the work of E. & G. G. Hook, whose 1843 Opus 50 for the Methodist Church of Westfield, Massachusetts, set Johnson on a career in organbuilding when he helped the Hooks with its installation.2 In this essay we will explore Johnson’s Opus 161 in detail and contrast it with the Opus 322 of the Hooks, both of which were constructed within a year of each other.3 While the Hooks used a Germanic constant scale in their pipe construction, Johnson significantly reduced the scale of his upperwork stops, much in the manner of Samuel Green and classical French builders.

The question arises as to whether Johnson came to his design theory by way of a process of convergent evolution (i.e., independently), or whether he was exposed to the organ Samuel Green shipped to the Battle Square Church in Boston in 1792, and which “was played virtually unaltered for a century,” according to Barbara Owen.4 The author suggested to Owen that the Green organ may have had a strong influence on Johnson, but she thought it unlikely that Johnson would have made the long trip from Westfield, far to the west of Boston. 

Travel would indeed have been much more difficult in 1843 when Johnson was exposed to the Hook organ at Westfield. But of some significance was the extension of the Western Railroad from Boston to Westfield in 1843. This new railroad may have been the means by which the Hook organ was shipped to Westfield. Elsworth (see endnote 2) clearly makes the case that Johnson was intoxicated by organbuilding with his exposure to the Hook organ. It is easy to imagine that he would have made a pilgrimage to Boston, at the time a mecca of American organbuilding, perhaps invited by the Hooks to accompany them after finishing their installation in Westfield.5

The author was engaged in 1976 by Mrs. Gene Davis, the organist of the Piru Community United Methodist Church, to evaluate the organ at that church. The identity of the organ was in question as no nameplate was in evidence on the console, the organ was barely playable, and its sound was greatly muted by the crude placement of panels in front of the Great division to make it expressive by forcing its sound through the shades of the Swell division above it. An inspection showed that nearly all of the pipework was intact, and a contract was signed to restore the organ to playable condition. The organ was cleaned, the pipes repaired, the few missing pipes replaced, and much of the action repaired by Michael McNeil and David Sedlak.

The church office files produced an undated, typed document that stated: 


The pipe organ in the Methodist Church of Piru was built by William Johnson, of Westfield, Mass., in the early 1860s, making it probably the oldest operating pipe organ in California. It was a second-hand organ when transported by sailing ship 17,000 miles around Cape Horn before 1900, and installed in a Roman Catholic Church in San Francisco. After the earthquake and fire of 1906, the organ was moved to another church and probably at this time parts damaged in the quake were replaced. After many more years of service it was retired and put into storage until, in 1935, Mr. Hugh Warring was persuaded to purchase it for the Piru church. It was purchased for the storage cost of $280.

Evidence of a different and more likely provenance was discovered during the removal of pipework and the cleaning of the organ. Three labels were found glued to the bottom of the reservoir (perhaps as patches for leaks). Two labels read: “Geo. Putnam ‘Janitor’ Stockton California July 1 ’99.” A third label read: “From the Periodical Department, Presbyterian Board of Publication, and Sabbath = Schoolwork, Witherspoon Bldg, 1319 Walnut St., Phila. PA.” At a much later time Reverend Thomas Carroll, SJ, noticed that the clues of Stockton, California, and the Presbyterian church correlated to an entry in the opus list of Johnson organs, compiled in Elsworth’s 1984 book, The Johnson Organs. Opus 161 was shipped in 1864 to the “Presbyterian Church, Stockton, Cal. The church is Eastside Presbyterian.” The organ was listed as having two manuals and 22 stops.6 At this time such features as couplers and tremulants were counted as “stops,” and this roughly fit the description of the Piru organ. The façade of the Piru organ is also consistent with the architecture of organs built by Johnson in the 1864 time frame. Elsworth’s illustrations include a console layout of Opus 200 (1866) virtually identical to the Piru organ layout; Opus 134 (1862) exhibits the impost, stiles, and Gothic ornamentation of the Piru organ; Opus 183 (1865) has similar pipe flats and also the console layout of the Piru organ.7 Many other details verified the Johnson pedigree, among them the inscription “H. T. Levi” on the reed pipes. Barbara Owen pointed out that Levi was Johnson’s reed voicer during the time of manufacture of Opus 161.8 The pieces of evidence fell together when Jim Lewis discovered a newspaper photo of Opus 161 in the Eastside Presbyterian Church of Stockton that matched the façade of the Piru organ. The most likely scenario is that Johnson shipped Opus 161 directly to that church. The Gothic architecture of the Johnson façade also reflects the architecture of the Eastside Presbyterian Church façade. A handwritten note on the Piru church document stated: “Pipe organ and art glass memorial windows dedication June 2, 1935 per Fillmore Herald May 31, 1935, a gift of Hugh Warring.”

It is possible that the organ went from the Presbyterian church into storage, and was later moved to its present location in the 1934–1935 time frame. Even so, we can say with nearly absolute certainty that this organ is William A. Johnson’s Opus 161.


Tonal design overview

It is obvious from even a casual glance at Elsworth’s study of Johnson organs that the Johnson tonal style was based on a classical principal chorus that included mixtures in all but the more modest instruments. But the voicing style is gentle and refined, and bears great similarity to the late-eighteenth-century English work of Samuel Green, whose meantone organ at Armitage in Staffordshire is an excellent surviving example.9 Tuned in meantone, Johnson Opus 161 would easily pass muster as the work of Green. The tonal contrast between Green and Hook is stark, and the Hook data serve as an excellent counterpoint to the data from the Johnson organ. Green was the organbuilder favored by the organizers of the Handel Commemoration Festival of 1784, who went so far as to have one of Green’s organs temporarily installed in Westminster Abbey for that occasion. King George III paid Samuel Green to build an organ for Saint George’s Chapel at Windsor.

Stephen Bicknell’s The History of the English Organ relates important details of Samuel Green’s work that we find in Johnson’s Opus 161. “. . . Green’s voicing broke new ground . . . . Delicacy was achieved partly by reducing the size of the pipe foot and by increasing the amount of nicking. The loss of grandeur in the chorus was made up for by increasing the scales of the extreme basses.”10 And “Where Snetzler provided a chorus of startling boldness and with all the open metal ranks of equal power, Green introduced refinement and delicacy and modified the power of the off-unison ranks to secure a new kind of blend.”11 The Hooks, like Snetzler, used a constant scale where all of the pipes in the principal chorus at a given pitch had about the same scale and power.

The most basic data set for describing power balances and voicing must include, at a minimum, pipe diameters, widths of mouths, heights of mouths (“cutup”), diameters of foot toe holes, and depths of mouth flueways. The data in this essay are presented in normalized scales for inside pipe diameters, mouth widths, and mouth heights. Tables showing how raw data are converted into normalized scales may be found in the article on the E. & G. G. Hook Opus 322 published in The Diapason, July 2017. The full set of Johnson data and the Excel spreadsheet used to analyze them may be obtained at no charge by emailing the author.12 Also available is the book The Sound of Pipe Organs, which describes in detail the theory and derivation of the models used in this essay.13


Pitch, wind pressure, and general notes

The current pitch of the Johnson and Hook organs is dissimilar and should be taken into consideration when observing the scaling charts. The Hook organ is now pitched at A=435.3 Hz at 74 degrees Fahrenheit, while the Johnson organ is now pitched at 440 Hz. The original pitch of the Hook organ was 450 Hz; new low C pipes were added when the pitch was changed to 435 Hz, and the original pipework was moved up a halftone, widening its scales by a halftone. The original pitch of the Johnson organ was approximately 450 Hz; the pipes were lengthened to achieve a lower pitch.14 The Hook and Johnson organs are both tuned in equal temperament. The wind pressure, water column, of the Hook is 76 mm (3 inches); the Johnson organ was measured at 76 mm static and 70 mm under full flow on the Great division. The pressure was reduced during the restoration to 63 mm static. This allowed the pitch of the pipes to drop, making the adjustment to 440 Hz with fewer changes to the pipe lengths; most of the pipes that were originally cut to length had been crudely pinched at the top to lower their pitch. With the reduction in pressure the ears of the 4 Flute à Cheminée, with its soldered tops, achieved a more normal position. 

The Piru room acoustic was reasonably efficient, and while the Johnson voicing is very restrained, it was adequate to fill this room on the reduced pressure. The Piru church seats 109, has plastered walls, wood and carpet flooring, and a peaked ceiling about 30 feet high; the reverberation, empty, as heard with normal ears, is well under one second (this is not the measurement used by architects that erroneously reports much longer reverberation). Elsworth relates that “the wind pressure which Johnson used during this period was generally between 212 and 234 inches [63.5 and 70 mm], and, in rare examples, nearly 3 inches [76 mm].”15 The photograph of the original Eastside Presbyterian Church for which the Johnson was designed implies a larger acoustical space than that of the Piru church.

The compass of the Johnson organ is 56 notes in the manuals, C to g′′′, and 27 notes in the pedal, C to d.



The Johnson console was found in poor condition, missing the builder’s nameplate and many of its stop knob faces. Correct stop names were derived from the markings on the pipes and the missing faces were replaced. The original stoplist is reconstructed as follows (Johnson did not use pitch designations):


8 Open Diapason

8 Keraulophon

8 Clarabella

4 Principal

4 Flute à Cheminée (TC)

223 Twelfth

2 Fifteenth

8 Trumpet


16 Bourdon (TC)

8 Open Diapason

8 Stopped Diapason

8 Viol d’Amour (TF)

4 Principal

8 Hautboy (TF)



16 Double Open Diapason



Great to Pedal

Swell to Pedal

Swell to Great


Blower signal

The above list adds up to 20 controls. The Johnson company opus list describes Opus 161 as having 22 “stops.” This may have reflected the original intention to supply the organ with stops having split basses, which are commonly found in Johnson specifications. The sliders for the Keraulophon and the Trumpet were found with separate bass sections from C to B, professionally screwed together with the sections from tenor C to d′′′. The two additional bass stops would account for a total of 22 “stops.” There are no extra holes in the stop jambs to indicate the deleted split bass stop actions. The extant stopjambs are apparently a later modification from the time of the installation at Piru or before. Elsworth noted that all Johnson organs of this period were constructed with square stop shanks.16 The current shanks are round where they pass through the stopjambs and are square where they connect to the stop action.

Several stop knobs were switched during the 1935 installation at Piru; e. g., the Viole d’Amour in the pre-restoration photo of the right jamb belongs in the position noted on the left jamb with the black plastic label “Bell Gamba,” which indeed is how this stop was constructed. The Swell Stopped Diapason was operated by a knob labeled “Principal” [sic]. The illustrations of the left stopjamb and right stopjamb diagrams provide the correct nomenclature as restored in the correct positions, with the incorrect 1935 nomenclature in parentheses ( ) and the correct pitches in brackets [ ].


The wind system

The wind system can be modeled from two viewpoints: the restriction of flow from the wind trunks, pallets, channels, and pipe toes; and the dynamics of the wind. Wind dynamics are fully explained in The Sound of Pipe Organs and are a very important aspect of an organ’s ability to sustain a fast tempo with stability or conversely to enhance the grand cadences of historic literature. The data set on the Johnson allows us to model all of these characteristics. Figure 1 shows the Johnson wind flow model.

In Figure 1 we see a table of the pipe toe diameters and their calculated areas; values in red font are calculations or interpolations from the data (e.g., wood pipe toes are difficult to measure when they have wooden wedges to restrict flow). These areas are measured for a single note in each octave of the compass.

A model for the total required wind flow of the full plenum of the organ assumes a maximum of ten pallets (a ten-fingered chord), as described in the table, and the flow is multiplied by the number of the pallets played for each octave in the compass. The sum of the toe areas of all ten manual pallets in the tutti is 5,057 mm2. The total area of the manual wind trunks is 38,872 mm2, and we see that the wind trunks afford 7.7 times more wind than the tutti requires, so much in fact that the trunks do not at all function as an effective resistance in the system.

Interestingly, the Isnard organ at St. Maximin, France, used the main wind trunk as a strong resistor to dampen Helmholtz resonances in the wind system, and that organ has ratios of wind trunk area to a plenum toe area of only 1.07 for the coupled principal chorus of the Grand-Orgue and Positif, but with no reeds, flutes, or mutations. Helmholtz resonances are the source of what is normally called wind shake, and we would expect some mild wind shake with the Johnson’s large wind ducts and low damping resistance. The author’s notes from 1976 state: “Very little sustained shake . . . a considerable fluctuation in pitch when playing moderately fast legato scales, which stabilizes very rapidly . . . this imparts a shimmer . . . .”

In Figure 1 we also see dimensions of the key channels, pallet openings, and the pallet pull length (estimated from the ratios in the action). These allow us to calculate the relative wind flow of the channels and pallets. We find that there are robust margins in wind flow from the channels to the pipe toes (244% at low C to 737% at high C on the Great). This accounts for the small drop in static pressure at 76 mm to a full flow pressure of 70 mm with all stops drawn. Pallet openings are less robust and flow about 100% of the channel area for the first three octaves and 190% in the high treble.

The underlying dynamics of a wind system are the result of the mass of its bellows plate and the volume of air in the system. These factors produce a natural resonance that can enhance the grand cadences of literature with a long surge in the wind, or it can produce a nervous shake if it is too fast. A grand surge in the wind is characterized by a resonant frequency of less than 2 Hz (cycles per second), and it is most often produced by a weighted bellows. A nervous shake results from a sprung bellows. We correct the latter condition with small concussion bellows in modern organs, but the Johnson organ does not have such devices; instead, it features only a large, weighted, double-rise bellows. 

We can model the dynamic response of an organ by using its wind pressure, the area of the bellows plates, and the combined internal volume of its bellows, wind trunks, and pallet boxes. The model in Figure 2 shows the dynamic response of the current Johnson wind system at a relaxed 1.61 Hz. This low resonant frequency drops further to 1.47 Hz when the pressure is raised to its original value of 76 mm. The author’s notes from 1976 state: “Light ‘give’ on full organ; relatively fast buildup to full flow.” That “light give” is the result of the low resonant frequency of the system. The resonant frequency of the Hook organ was modeled at 1.23 Hz, a value lower than the Johnson, and the Hook chorus does indeed exhibit a slower and grander surge on full organ. Figure 3 shows the modeled resonant frequency at the original pressure of 76 mm for the Johnson organ. The equation for modeling the resonant frequency of a wind system along with a worked example on the 1774 Isnard organ at St. Maximin may be found in The Sound of Pipe Organs, pages 99–113.


The wind system in pictures

See the accompanying pictures: Notebook sketch 1, Great windchest, Toeboard, Notebook sketch 2, Notebook sketch 3, Notebook sketch 4, Great pallet box, Pallet springs, Notebook sketch 5.


The layout in pictures

“Green’s organs stand on an independent building frame with the case erected around it, rather than being supported by the structure of the case itself.”17 Bicknell’s description of a Samuel Green organ applies equally well to this Johnson organ. The casework is built entirely of black walnut, a wood mentioned by Elsworth in reference to Johnson cases. The organ is situated within the front wall of the church. The original black walnut side panels (typical of early Johnson organs) were found crudely cut up and nailed behind the façade in an effort to make the whole organ expressive through the Swell shades. This had the effect of making the Great division sound like a diminutive Echo division. The typical layout of a Johnson organ is well described by Elsworth: “The framework was arranged to carry the chests of the Great organ and the supporting framework for the Swell, which was usually above the Great organ and slightly to the rear.”18 Such layouts, shown in Figure 4, are common in nineteenth-century American organbuilding. The walkway behind the Great allowed access to the pipes and pallets placed at the rear of that chest, and the rollerboard to the Swell division was normally placed just behind this walkway, allowing access to the Swell pallets that were placed at the front of the Swell windchest. Opus 161 was installed in an opening in the Piru church that was far too shallow to allow the depth of a rearward placement of the Swell division. 

As a result, there is evidence that the Swell windchest may have been reversed, placing its pallets to the back of the windchest, and the chest brought forward over the Great division. Note the lack of clearance between the 4Principal pipe and the bottom of the Swell chest in Figure 5. The internal framework shows signs of crude saw cuts; the order of the notes on the Swell chest is the same as the Great, but it is reversed; the Swell rollerboard appears to have been likewise reversed and now faces toward the walkway where the action and rollers are exposed to damage. 

To say that the Piru layout was cramped would be an understatement; no one weighing over 150 pounds would gain access to the pipes for tuning or to the action for adjustment without damaging the pipework or the key action. The author weighed less (at the time) and was barely able to navigate inside the organ. The current layout is shown in Figure 6

It is also possible that the current layout reflects the original layout by Johnson, but that the Swell was simply lowered to fit the height of the Piru church and brought forward to fit the limited depth available, reducing the depth of the walkway.

Notes and credits

All photos, drawings, tables, and illustrations are courtesy of the author’s collection if not otherwise noted. Most of the color photos were unfortunately taken by the author with an inferior camera in low resolution. David Sedlak used a high quality camera, lenses, and film to produce the high-resolution color photos of the church and its architectural details; these are all attributed to Sedlak.

1. Stephen Bicknell, The History of the English Organ, Cambridge University Press, 1996, Cambridge, pp. 185–187, 190–191, 207.

2. John Van Varick Elsworth, The Johnson Organs, The Boston Organ Club, 1984, Harrisville, p. 18.

3. A detailed study of the E. & G. G. Hook Opus 322 may be found in The Diapason, July, August, and September issues, 2017.

4. Barbara Owen, The Organ in New England, The Sunbury Press, 1979, Raleigh, pp. 18–19.

5. see:

6. The Johnson Organs, p. 100.

7. Ibid, pp. 23, 50, 57, respectively.

8. The Organ in New England, p. 275.

9. 5 Organ Concertos, 1984, Archiv D 150066, Simon Preston, Trevor Pinnock, The English Concert.

10. The History of the English Organ, p. 185.

11. Ibid, p. 207.

12. McNeil, Michael. Johnson_161_170807, an Excel file containing all of the raw data and the models used to analyze the Johnson Opus 161, 2017, available by emailing the author at [email protected].

13. McNeil, Michael. The Sound of Pipe Organs, CC&A, Mead, 2012, 191 pp.,

14. The Organ in New England, p. 75.

15. The Johnson Organs, p. 25.

16. Ibid, p. 23.

17. The History of the English Organ, p. 187.

18. The Johnson Organs, p. 23.


To be continued.

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