| In the 1920s, before the era of the magnetic pick-up and the electric guitar, the biggest impetus to innovative guitar design was making a louder guitar. Designers sought a variety of ingenious solutions, and one of the most innovative was developed by a family of Slovakian immigrants living in California: the Dopyera Brothers. Banjo maker John Dopyera was approached by vaudeville guitarist George Beauchamp with a simple request: he wanted a louder intrument.
Dopyera's solution was to integrate the acoustic principles behind a regular loudspeaker into the body of the guitar, and so was born the resonator guitar. He fitted a floating aluminium "cone" into the top of the guitar body and affixed the bridge to it. Vibrations from the strings passed through the bridge saddles into the cone which resonated back and forth in a manner similar to a loudspeaker, creating a distinctive metallic jangle. Although this sound was not to the liking of all guitarists, it was certainly much louder than any other guitar of the era.
The first guitars of this type were built for the National guitar company in 1926; these were the National Style O. In 1927, however, John, Rudy, and Ed Dopyera broke away to form their own company, Dobro, producing an alternative resonator guitar. This guitar had a regular wood body with the aluminium resonator fixed into the top of the soundboard; the National Style O was all aluminium (except for, of course, the fretboard).
Over the years, many different guitar companies have experimented with and produced variations on the resonator principle. Dobro themselves bought National in 1932 but then turned their attention to the coming electric age and sold the right to the Dobro name to Regal. In the 60s, Mosrite produced Dobro-branded resonators, creating also 12-string and bass versions. Also in the 60s, Emil Dopyera, son of Ed, began making resonators under the company name Original Music Instruments, but was bought out by Gibson in the 1993 after a not-very-successful life. Gibson continue to market both wooden and metal resonators under the famous Dobro brand. The idea of the resonator guitar is so strongly linked to the Dopyera brothers, however, that resonator guitars - irrespective of the real brand - are often generically referred to as "dobros".
Famous dobro players include:
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