Acoustic guitars, often made of aluminum, that produce sound through resonators rather than through the sound box. From the late 1920s, resonator guitars were popularized for their volume, and began to regularly appear in bluegrass ensembles. They are often referred to generally as dobro guitars, although the Dobro company’s resonator guitar is a specific type with a single resonator, and designed differently than those resonator guitars made by National, for example, which have three resonator cones (called “tricone”).
