Loar’s Contributions to Instrument Design

Lloyd Loar Lloyd Allayre Loar made many contributions to the world of music through his developments of piano key actions and amplified instruments, but it is his advancements in acoustic stringed instrument technology while working for Gibson for which Loar is widely known today. “Lloyd was always searching for something,” his wife Bertha would remark, referring to his interest in musical developments. And, the instruments he played were always different in some way. The first Gibson F2 three-point mandolin he owned, shown in this cameo (below, left) from the Gibson 1908 “F” catalog, boasted a unique pickguard that covered and protected the end of the fretboard. The enlarged photo (center) shows how this pickguard extended across to the mandolin’s bass bout and went just to the edge of the soundhole. In the photo, the pickguard appears to be molded around the end of the fretboard as opposed to being elevated. (This cameo image was taken from the original photo shown on the previous “Loar’s Background” web page. The photo on the right, also taken from Gibson’s 1908 “F” catalog, shows the standard configuration of the early F2 three-point mandolin with it’s optional clamp-on fingerrest.)

Lloyd Loar with 3 point 3 point close-up 3 point with F2

Loar went to work at Gibson in 1918, the same year Orville Gibson left the company. But little is known of whether these two events had any relationship to each other or how close their relationship was. Under Loar’s guidance, soundboards and backboards for Gibson’s Master Model mandolins, mandolas, and guitars were carefully graduated from their thickest to their thinnest regions. For mandolins, this called for soundboards and backboards to be carved to about .110″ in the thinnest or “minimum area” (about 1″ in from the perimeter) and about .180″ at the center. Since these components were later “tuned,” the final thickness would differ from instrument to instrument depending on the stiffness of the wood, grain distribution, density, etc. Soundboards were also arched to give them strength. The graduation from the center outwards provided for a means of efficient distribution and transfer of energy (from the bridge outwards). This carving technique, often called “Stradivarius arching,” allowed the soundboard and backboard to “pump” like the paper cone of a common speaker, generating greater compression and rarefaction within the instrument’s air chamber; a movement that provided theses instruments with greater amplitude then their former counterparts.

Mandolin back The “Stradivarius arching” or tortoise shell shape provided the backboard and soundboard with great strength without the need for additional structural bracing. But more importantly, the graduation from a thick center to a thin outer portion imparted to these “plates” the ability to evenly distribute energy from the center (where the bridge was mounted) outwards.

(This photo demonstrates the type of arching and shape of a maple backboard that was used on the F5 mandolins. The wavy lines across the backboard are caused by the curly maple figure.)

  Longitudinal tone bars were also “tuned” by thinning them to adjust the stiffness of the soundboard. The bass bar and treble bar were positioned in a non-symmetrical manner, and sized differently so that the treble side and bass side of the soundboard could be separately adjusted (i.e. the two tone bars were not symmetrically positioned). By removing wood from the tone bar, the soundboard would become less stiff, resulting in a lowered pitch. By tuning the tone bars to a specific note, Gibson engineers could be assured of likewise adjusting the soundboard to a known and very repeatable stiffness. The tuning process is so controllable that a whole-tone difference could be attained between the two tone bars. As a final tuning step, the f-hole openings were also “tuned”. To do this, the size of the f-holes was adjusted after the instrument was assembled, to achieve the final tuning of the instrument. As the f-holes were made wider (larger), the pitch of the air chamber would be raised until the proper note was achieved.

F5 Mandolin While Loar did extensive work on electric keyboards and amplified stringed instruments, his association with those developments did not endure to today. By contrast, the name “Loar” is heralded as the penultimate creator of the bluegrass mandolin. Clearly, Bill Monroe brought the mandolin into the spotlight, but the sound we associate with Monroe’s instrument came from Lloyd Loar.

The F5 mandolin was a major departure for Gibson. It provided the same 13-15/16″ string scale as on previous mandolin models, but the F5 featured an extended neck with 12 frets clear of the body. The soundboard and backboard were carefully graduated and tuned, as were the tone bars and f-holes.

  Cosmetic variations appeared in hand-rubbed “Cremona” finishes ranging from almost black to rich dark brown. Variations of white/black/white binding were used on the Loar-signed F5s and the instrument was adorned with either silver- and gold-plated hardware and either “fern” or “flowerpot” inlay patterns on the peghead. All featured dot inlays, as shown here. About 250 of these instruments were built by Gibson and Lloyd Loar personally approved the tuning, and signed the labels in each one (see labels, below). Loar followed the teachings of Hermann L. F. Helmholz (1821-1894) who studied the resonant frequencies of variously sized air chambers. Loar carefully sized the air chambers and f-holes of the instruments he designed to provide a correctly tuned space for each type and size of instrument. Since an adjustment to one part of the instrument effects the tuning of another part, one can appreciate the hours of trial and error that preceded the development and subsequent finalization of the dimensions of Gibson’s “Master Model” instruments. As final proof of the hand-tuning process, Loar gave his signature on a label inside the instrument attesting that “The top, back, tone-bars, and air-chamber of this instrument were tested, tuned and the assemble(d) instrument tried and approved ___(date)___.”

The Gibson Master Model label with Loar's signatureEach of the Gibson “Master Model” instruments featured a signed label which attested to the tuning process applied to that instrument. While Loar didn’t actually build the instruments themselves, he did test each one to ensure they were properly tuned, and then signed and dated the labels

  Loar’s tunings would have been unusual for us today, because they were based on having concert pitch at C256, a tuning that has fourth octave A falling between A430 and A431. Today’s concert pitch is predicated on A440 which positions C at 261.63Hz. This misalignment of tunings is one of the main attributes that gives F5s their great voice, today. (For more information, you may wish to click here to download a study entitled What was Loar Hearing? – 1M.) During Loar’s tenure at Gibson he developed an A-model mandolin that boasted all of the features of the F5 but had a simple tapered peghead with a fleur-de-lis inlay, and a pear-shaped body that was absent of the body scroll and body points. This “A5” model featured f-holes but since the body was slightly smaller than an F5, the resonant frequency of the air chamber was naturally higher than an F5 requiring the f-holes to be smaller in order to tune the air chamber to a D#. The instrument had the famed “signature labels” (above) and while Gibson was later to make pear-shaped mandolins with f-holes, this model was never cataloged by Gibson. This instrument is richly detailed in our A5 Pro-Series Drawing set.

A5 Mandolin The A5 boasted many features of it’s F5 counterpart. One major departure from the F5 design was the positioning of the bridge high above the centerline of the body in what appears to be an attempt to gain more live soundboard area than was achieved on F5 models. This also called for an accentuated headblock. The f-holes are slightly further outboard than those on the F5 and are sized about 15% smaller than those on the F5 to deliver a lower-than-natural voicing of the instrument’s air chamber. The binding on the lower corners of the peghead are bent rather than mortised and the peghead’s binding joins in a mortised “V” joint at the top center of the peghead. Loar elaborated on the pear-shaped f-hole body with an even greater Venetian flair for his ViviTone mandolin designs (below). [The instrument pictured here was signed and dated on Sept 10, 1923.]

Another Loar contribution to the tonal characteristics of Gibson’s mandolins was addition of “Virzi Tone Producers” affixed to the inside of the soundboard on some of the “Master Model” instruments and on his personal F5 mandolin. The Tone Producer was a disc made of spruce with two f-hole-like apertures, which was affixed to the underside of the soundboard with a single rear foot and a double front foot. It was the intention of the Virzi brothers, who patented this design, that the Tone Producer would impart a better overtone series to the instrument. While the Tone Producer’s popularity did not survive to today’s instruments, it gained popularity with classical players during the 20s and 30s and was heavily promoted to performers on violin-family instruments. Loar was a consultant to Virzi and his photo and bio appear in the Virzi literature. His own personal viola (made by August Diehl) also boasts a Virzi Tone Producer.

H5 Mandola While not as popular as the L5 guitars and F5 mandolins of the period, the H5 Master Model mandola was another interesting development produced under Loar’s direction.This instrument is 11″ wide and almost 30″ long and features a carved soundboard and backboard with tuned air chamber as did other models in Gibson’s Master Model line. The H5’s fretboard connected to the body at the 13th fret (instead of at the 15th as on the F5) and it featured a 15-5/8″ string scale.

Some discussion in various luthiery chat rooms suggests that to achieve the correct body shape for the H5, “the commercially available F5 plans can be scaled up 15%.” Actually, that’s a bit misleading as the H5 has very different body proportions, scroll shape, bridge placement, peghead shape, f-hole position and scaling, fretboard shape, and more.

(Photo courtesy George Gruhn)

If one had to sum up and highlight Loar’s most significant contribution to acoustic instruments, it would have to be in the area of “tuning.” The art of tuning was not merely adjusting the strings to the correct pitch but rather tuning the various structural components of the instrument to specific pitches so that the whole instrument worked as a coupled system (acoustically speaking), producing the best tones possible from each of its parts and from the instrument as a whole. In this regard soundboards, backboards, tone bars, f-holes, and air chamber sizes were adjusted so that each element was tuned to a specific note that resided on a scale that used A440 as its calibration point (historically, A was not always 440Hz). With the entire instrument assembled, and strings tuned (also to a scale that also used A440 as their calibration point), the parts of the instrument responded harmonically to the strings’ energy rather than discordantly, and avoided any unwanted “beats” or overtones thus bringing forth the best dynamics and tonal qualities of the instrument. After his stint with Gibson, and excited by the potential of his developments for tuning mandolins and guitars, Loar carried his ideas to the massive soundboards of pianos (see US Pat 1,798,212 in Loar patents) which ignited further expansion of a new line of keyboard and fretted instruments under the name “ViViTone.”

Loar Clavicord darwing Loar was a performing artist, an engineering “artist,” and as we have discovered, an artist with pencil and paper. Uncovered with his personal papers were many drawings and sketches of instrument designs and instrument parts. One of many of Loar’s drawings, is this of the ViviTone clavier (see photo below). It was drawn in pencil on a paper bag. c:1937

Loar spent his later years (1935-1943) creating devices for amplifying musical instruments, developing keyboard actions, and creating tone producing systems for electric pianos. His approach to acoustic stringed instrument design was centered on two major aspects of construction: First, he strove to obtain maximum tone and power from the instrument by adjusting its components to most effectively drive compression and rarefaction (the two pressure-producing modes of sound waves). Secondly, appreciating that the instrument itself produced a note (or notes) which was part of the overall tone, he attempted to tune the instrument and its parts.

Speaker cabinet with Loar's ViviTone Clavier feature The speaker cabinet that accompanied Loar’s ViviTone Clavier features a 110v motor that rotates a fan-like blade. The blade turns in front of the powered-coil speaker as well as covering and uncovering an opening to the cabinet itself. This feature provided a tremolo that added timbre (tone “color”) to the erstwhile poor sound of his early electronic amplification system.

  Paper-cone speakers were in their infantile stages during the period that Loar was playing with electronic amplification, and the tube-amps and electronics he used were prone to background noise and hum. To add vibrato and improve the tonal qualities of these early systems, Loar placed moving baffles in front of the speakers in his speaker cabinets. In the system shown above, a spinning blade blocks the output from the speaker as well as from the bass response and resonant frequency of the speaker’s cabinet. In another system, (not shown) a vertical paddle turns in front of a speaker to induce a tremolo effect. Loar used foot control buttons to turn the motors on and off. Unfortunately, the mechanics were not very efficient and the motor, fan belt, and spinning blades were a bit noisy.

ViviTone Clavier As testament to Loar’s work, his personal clavier (shown here) was in perfect tune when it was first discovered and unpacked 50 years after his death. Unfortunately, the War years, coupled with lack of financing, made it difficult for Loar to advance his art and his business, and the production of ViViTone instruments came to premature end.

Loar worked hard to develop his line of ViViTone instruments. He focused to provide instruments that would be powerful and would stay in tune (a frustration spurred by the poor steel strings of the day). His ViViTone Clavier was an amplified instrument that used small bars that would chime when tapped by the key action. Since the bars were not stretched (as strings are in a piano), it was his intention that these instruments would always be in tune. His dream came true; his clavier (above) was still in perfect tune when it was uncrated 50 years after he packed it!

 Electric Viola front view Electric Viola back view Electric Viola profile
Following the design of Loar’s prototype for his electric viola the production model for his ViviTone electric violins featured a flat soundboard with painted f-holes (no air chamber), a heavy ebony fretboard, and an electromagnetic pickup. (Photo courtesy of the National Music Museum, University of South Dakota, Vermillion, South Dakota.) For more information on the Loar collection at the museum, click here.


Loar ViviTone GuitarLoar ViviTone GuitarThe ViViTone guitar and ViViTone mandolin were available in both acoustic and electric models. The ViViTone instruments featured f-holes, white pegheads with a black silk-screened logo and a dark, hand rubbed Cremona brown finish.

The non-keyboard ViViTone instruments were unique and featured a laminated and very-rigid rim with both the soundboard and the backboard made from spruce. Coil-wound pickups were employed to amplify sound, and the soundboard, tone bars, backboards, and f-holes were carefully tuned to deliver a rich, balanced tone. While these instruments delivered a new and exciting sound for musicians of the period, the lasting effects of the Depression and the beginning effects of World War II smothered the music Loar was making and prevented Loar from raising the needed cash to grow his business and market his line of instruments. ViViTone and Loar’s dream came to a screeching halt. Early in 1940, While partner Lewis Williams continued to make ViViTone guitars in Kalamazoo, Loar went back to Chicago to look for investors, promote the keyboard line, help Frank Holton sell his business, and do whatever he could to promote his designs and ideas. But through his frustrations, and probably to keep his mind fresh, Loar continued to teach music theory at Northwestern University see lab notebook — the one thing he loved most — until his death in September of 1943.

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