A dobro is an acoustic guitar with a metal resonator built into its body. This resonator serves as an amplifier. In contrast to acoustic guitars, the placement of the resonator takes place of the sound hole. Therefore the shape of the guitar doesn’t tend to have an affect on how the dobro’s sound is amplified.

The dobro was invented by John Dopyera in the early 1930s. Dopyera and his brother struck out in the late 20s in search of a way to create a louder guitar. The brothers called their new company Dobro, which meant “good” in their native language.

Dobros sound more like banjos than guitars, because of the effect created by the metal strings played over the metal plate. This is employed even further by players who use a metal slide (rather than fingering chords with their fretting hand, the way an acoustic guitar player does).