The resonator guitar
As the guitar became more readily available and gained in popularity it made the transition from rhythm to playing the melody. Now, the guitar is a quiet instrument without amplification and this posed a problem for guitarists sharing the stage with other, more vocal instruments. Imagine the poor guitar player in an early jazz band, struggling to be heard over the brass and reed instruments.
Even the lone busker playing and singing on the street corner knew that in order for his hat to fill with coins he had to be heard above the sounds of the city.
An inventive musician from Los Angeles by the name of George Beauchamp is credited with coming up with the basic idea of making the guitar louder. Beauchamp hooked up with John and Rudy Dopyera who had already made improvements to the banjo by adding a resonator to the back.
The resulting design included a set of three metal cones connected at their apex to a “T” shaped metal bridge, an arrangement that would later be known as the Tricone design. This assembly was suspended inside a guitar body made of metal and formed a resonating chamber sort of like a modern speaker cabinet. Strumming the strings caused the metal cones to vibrate and mechanically amplify the sound.
In 1927 Beauchamp and John Dopyera incorporated their business as the National Stringed Instrument Corporation and sold their instruments under the National brand. In 1928 John Dopyera left National and along with four of his brothers formed a competing business. The brothers named their new business the Dobro Manufacturing Company. The name is a contraction of Dopyera Brothers and had the side benefit of meaning “good” in their native Slovak language.
The Dobro differed from the National in that it used a single inverted cone as a resonator as opposed to the tricone design. The single cone design produced a much louder sound than the tricone and was much cheaper to produce. National soon came out with their own single cone guitar, although the National design was attached opposite of the Dobro cone with a small wooden “biscuit” at the apex attached to the bridge. John Dopyera, who still owned a controlling interest in National, claimed to have designed the single cone while still at National. In 1932, after a long legal battle, the Dopyera brothers gained control of both companies and merged them as the National Dobro Corporation.
During WWII all production of resonator guitars was halted due to the shortage of the steel and aluminum.
The round necked National with its steel body became popular with blues musicians who preferred to play it with a bottleneck slide. Hawaiian musicians preferred the square necked, steel body played lap style (laid flat with the strings up). Bluegrass musicians took to the square necked and wood bodied Dobro, most often playing it lap style.
Pictured here is a 1933 National Duolian just like the one I bought at an estate auction many years ago. When my eldest son was but a baby and having trouble sleeping at night, I would rock his cradle with my foot and play some soft bottleneck blues on that old National until he drifted off to sleep again. Today my son is a DJ and cohosts a local radio show, but has no interest in the blues. I didn’t think I played that badly.