| More and more often these days, an instrument | | | | and began his own label, Dobro. That company |
| originally designed for one purpose or musical genre | | | | released a competing resonator guitar that featured |
| will be adopted for and adapted to a completely | | | | a single resonator under a distinctive circular |
| different area. This has been the fate of the | | | | perforated metal cover plate. The bridge rested at |
| resonator guitar, which was originally designed to be | | | | the center of this plate on an eight-legged aluminum |
| louder than a conventional acoustic guitar in order to | | | | spider. Finally, National countered with its own take on |
| ensure that the instrument could be heard above the | | | | the single resonator model. This instrument used a |
| horns and percussion instruments in dance orchestras. | | | | wooden "biscuit" at the cone apex to support the |
| The resonator guitar, however, is possessed of a | | | | bridge, rather than the traditional spider. |
| very distinct and original sound, and because of that, | | | | This quick succession of instrument innovations |
| it has been adopted and integrated into the musical | | | | occurred over the course of about five years. At the |
| genres of bluegrass, country and blues music. | | | | end of that time, in 1932, the owners of Dobro |
| The resonator guitar, or resophonic guitar as it is | | | | gained control of National and formed the National |
| occasionally called, is an acoustic guitar that uses one | | | | Dobro Corporation. However, with the entry of the |
| or more metal cones (resonators) instead of the | | | | United States into World War II in 1941, all production |
| traditional wooden soundboard. These instruments | | | | of resonator guitars by the company ceased for a |
| can be divided into two subcategories, these being | | | | time. Since the end of World War II, the Dobro label |
| square-necked guitars and round-necked guitars. The | | | | has passed through various hands, all of which have |
| former are designed to be played like a lap steel | | | | used it to produce resonator guitars. Dobro is |
| guitar (with a slide), while the latter can be played as | | | | currently the possession of the Gibson Guitar |
| either a conventional classical guitar or as a steel | | | | Company. Today, common terminology uses Dobro |
| guitar. In addition to this division, there are also three | | | | to refer to an instrument with an inverted cone, |
| main types of resonator designs: the "tricone," the | | | | while National generally means an instrument with a |
| single inverted cone, and the spider-less single cone. | | | | non-inverted cone. |
| The original resonator guitar was developed during | | | | As mentioned, bluegrass, country and blues are the |
| the early 20th century and in 1927, the first | | | | usual territory of the resonator guitar. The first |
| instruments were manufactured under the brand | | | | generally utilizes square-necked Dobro guitars, while |
| name National. These guitars were of the tricone | | | | the latter two favor round-necked National |
| variety, which means that they had three conical | | | | instruments. Because both styles of guitar may be |
| resonators joined by a T-shaped piece of aluminum | | | | played as a lap steel guitar, this is the most common |
| called a "spider" that supported the bridge. A year | | | | position used by artists. However, round-necked |
| later, one of the founding members of National split | | | | guitars may be played in the traditional guitar position. |