They became prized for their distinctive tone, and found life with bluegrass music and the blues well after electric amplification solved the problem of inadequate volume.

[3][4][1] National countered the Dobro with its own single resonator model, which Dopyera had designed before he left the company.

In 1967, Rudy and Emile Dopyera formed the Original Musical Instrument Company (OMI) to manufacture resonator guitars, first branded Hound Dog.

Valco produced a large volume and variety of fretted instruments under many names, with National as its premium brand.

By the early 1960s, Valco again produced resonator guitars for mail order under the brand name National.

of São Paulo, Brazil, has produced a wide range of guitars and other string instruments since Angelo Del Vecchio founded the company in 1902.

In the 1930s, they began producing resonator guitars,[5] resulting in their most famous model: the Dinâmico, (their trade term for resophonic instruments).

In the late 1990s Amistar, a Czech Republic manufacturer, began marketing tricone resonator guitars.

It may be set up with a variety of action heights, ranging from the half-inch favored for steel guitar (making use of the frets almost impossible) to the small fraction of an inch used by conventional guitarists.

A compromise is most common, allowing use of a bottleneck on the top strings but also use of the frets as desired, with the guitar played in the conventional position.

The resonator guitar was introduced to bluegrass music by Josh Graves, who played with Flatt and Scruggs, in the mid-1950s.

Graves used the hard-driving, syncopated three-finger picking style developed by Earl Scruggs for the five-string banjo.

Tuning for the resonator guitar within the bluegrass genre is most often an open G with the strings pitched to D G D G B D or G B D G B D, from the lowest to highest.

Occasionally variant tunings are used, such as an open D: D A D F# A D. Other notable bluegrass players include Jerry Douglas, Mike Auldridge, Rob Ickes, Phil Leadbetter and Andy Hall.

Leon McAuliffe initially played a dobro before exclusively transitioning to electric lap and console steel guitars.

Many players in the 1920s and 1930s, including Bo Carter, and others like Bukka White, Son House, Tampa Red and Blind Boy Fuller, used the instruments because they were louder than standard acoustic guitars, which enabled them to play for a larger crowd in areas that did not yet have electricity for amplifiers.

The instrument is still used by some blues players, notably Taj Mahal, Eric Sardinas, Alvin Hart, The Deacon Brandon Reeves, Warren Haynes, Derek Trucks, Doyle Bramhall II, Roland Chadwick, John Hammond Jr., Roy Rogers, John Mooney, and Megan Lovell of Larkin Poe.

Mark Knopfler has also played the guitar, and his National resonator is pictured on the cover of the Dire Straits album Brothers in Arms.

An enormous number of combinations are possible, most can be found either on old or new instruments or both, and many styles of music can be played on any resonator guitar.

Though the original aim of the resonator was increased volume, some modern instruments incorporate electric pickups and related technology.

However, all acoustic and semi-acoustic styles are very sensitive to audio feedback, making the design and placement of these pickups extremely critical and specialized.