The men behind the making of the master model series
F-5 mandolin, L-5 guitar, H-5 mandola & K-5 mando-cello

Contrary to popular believe Lloyd Loar was NOT solely responsible for the development of the Master Model Series F-5 mandolin, L-5 guitar, H-5 mandola & K-5 mando-cello. Evidence suggests that it was much more of a collaborative effort between Loar and Ted McHugh, who was Gibson’s Chief Engineer, as well as L.A. Williams, Gibson’s General Manager. Williams had hired Loar as an acoustical engineer sometime after WWI in 1919 or early 1920. It was Williams'his idea to build set a "NEW WORLD STANDARD IN MANDOLIN MAKING" and far exceed Gibson’s top-of-the-line F-4 they had been manufacturing since 1904. In April 1917, Williams and A.J. Reams filed for a patent for “improvements in bodies of stringed musical instruments” (Pat No. 1,361,182). The patent was finally granted three years later in 1920, and it included several features that would eventually be used on the Master Model F-5 mandolin. Mainly, it called for a more pronounced graduation of the top & back, as well as an elevated fingerboard, which was not a feature on any previous mandolin model Gibson made. Sometime in 1921-22, the F-5 was given the green light by Williams who was banking on the fact that the dwindling “mandolin craze” of the early 20^th century was going to make a big comeback. Unfortunately, he was wrong and left Gibson in 1923 when the company was in dire straits financially. Luckily, it did not stop Gibson from finishing what he and others had started and by the end of 1923, Gibson had four new Master Model instruments that to this day, are some of the most revered and copied instruments in history.

Below: A page from Gibson's 1923 F-5 brochure extolling the virtues of their new F-5 Master Model mandolin.

Undoubtedly, Loar was responsible for additional design improvements and manufacturing processes, including extending the neck to 12-frets clear of the body, instead of ten on the F-4. He also introduced the process of “tap tuning”, a method of fine-tuning the tone of the mandolin by ‘tapping” the top & back, prior to assembly, and making adjustments to the thickness in order to achieve more volume even tonal response. Gibson referred to this as the “Stradivarius sounding-board and back-board” and promoted it as having "unprecedented volume and carrying power". Gibson also had Loar sign and date every instrument he “tap tuned” that Williams promoted in a special F-5 brochure as “two little labels that mean much” referring to the Gibson ‘guarantee label” and the Loar-signed label. The results are now very apparent as a Loar-signed F-5 can fetch as much as $500,000.00 or more in today’s vintage instrument market. When examining several of these Loar-signed instruments, it is clear that “tap tuning” was one of his sole responsibilities, but not actually building the mandolins themselves.

Below: "Two Little Labels That mean So Much" as it appeared a special Gibson F-5 brochure. On the left, Gibson's standard "guarantee label" and on the right, the infamous "Loar-signed" label.

 

Below: A comparison between the F-5 Master Mandolin and the F-4 from 1923's Catalog 'N' show the differences in design including the F5's 12-fret neck and elevated fingerboard vs. the 10-fret neck on the F4 with no elevated FB.

It was the responsibility of chief engineer, Ted McHugh to put all of these improvements into a practical and workable manufacturing process, including selection of materials, sizes & thickness, etc. McHugh would also be a key contributor by incorporating two of his new inventions, the adjustable truss rod and adjustable height mandolin bridge. All of these factors came together to create the Master Models as a giant leap forward in fretted musical instrument technology. The adjustable truss became of Gibson’s main selling features for all of its instruments for decades, a real testament to McHugh’s invaluable contributions as one of Gibson's "un-sung heros".

Below: Internal specs sheets that supposedly had Lloyd Loar's hand-written notes, but a hand-writing comparison of known letters from the National Music Museum clearly indicate that it's not his notes at all. 


It is also important to point out that the F-5 mandolin had top priority in the development cycle, and no doubt that Lew Williams was behind it pushing it hard into production. In fact, the F-5 mandolin was the only Master series instrument to appear in Gibson’s 1923 catalog ‘N’, as it was clear that the other three were not ready as of its printing. Some very interesting company documents surfaced several years ago that really help to shed some light of this particular piece of the puzzle. As you will see below, several internal price lists and manufacturing spec sheets did NOT include the L-5, H-5 & K-5 as of mid-1923.

Below left: An internal price list dated 4/15/23 that included the F-5 mandolin, but the L-5 didn't have a price listed and the H-5 & K-5 were not included at all. Below right: An internal sheet of manufacturing specs for the F-5, but it also did NOT include any information on the other three Master Model instruments.

Finally, by May or June of 1923, the other three model L-5 guitar, H-5 mandola and K-5 mando-cello were in production, but didn’t appear in a Gibson catalog until 1924. By this time both L.A. Williams and Lloyd Loar left Gibson leaving behind a tremendous legacy that lives on until this day.

Below: The L-5 Master Guitar, H-5 Master Mandola and K-5 Master Mando-cello as they appeared in Gibson's 1924 Catalog 'O'.