The usurper of the Banjo. The banjo was the popular rhythm Instrument of the 1920s and 1930s but the guitar gained popularity, overtaking it completely by the 1950s and becoming electric at about the same time. The electification was an attempt to increase the volume which was never as great as from a banjo.
The modern guitar is a Spanish derivative of the Lyre and Lute and is one of several guitars known at the time including the English Guitar and the Portuguese Guitar. The Portuguese Guitar is a 6 course variation of the Cittern. The English Guitar is a Portuguese Guitar made in England.
From the Greek kithara (lyre) and Persian Oud (Lute) the guitar slowly evolved in Spain via various intermediate instruments including the Vihuela and Gittern.
Now either classical (nylon) or steel strung six (or 12) string instruments used in popular music.
The body size and shape varies and each has a name. Common types of acoustic guitar are Travel, Classic, Dreadnought and Jumbo. All guitars are Fretted instruments except for some (usually electric) bass guitars which emulate the Double Bass.
These use a particular type of metal cone resonator rather than a soundboard. The metal soundboard is typically decorative and provides the frame for the resonator. Also called Dobros.