The tenor guitar is one of the least known members of the guitar family, which includes standard 6-string guitars and bass guitars among many others. Tenor guitars are generally tuned CGDA, like a mandola, viola or tenor banjo, although some are tuned like the top four strings of a standard guitar, DGBE or like an octave mandolin, GDAE. The tenor guitar has originally developed around 1920 so that tenor banjo players could switch to guitar easily. Later solid body electric tenor guitars were developed. There are also resonator tenor guitars such as those built by Dobro or National. Currently the Tenor Guitar is mainly used in Texas Style and Western Swing music, where it's often played in conjuction with a standard guitar to back up a fiddle. In the 1920's to the 70's, all the major guitar manufacturers built tenor guitars, but Gibson and Martin both stopped in the 70's, and not many companies still make them, although Martin recently released a new tenor guitar, and Gold Tone continues to manufacture them.