Parlor or parlour guitar usually refers to a type of acoustic guitar smaller than a Size No.0 Concert Guitar by C. F. Martin & Company.
The popularity of these guitars peaked from the late 19th century until the 1950s. Many blues and folk musicians have used smaller-bodied guitars, which were often more affordable, mass production models.
Parlor guitar has also come to denote a style of American guitar music from the 19th and early 20th centuries. Noted composers include William Foden, Winslow Hayden, William Bateman, Justin Holland, and Wilhelm Bischoff. The music for the guitar includes a variety of dance forms (waltz, schottische, polka), instrumental arrangements of popular songs, guitar arrangements of then popular classical music, operatic arrangements and music from European guitar composers (Sor, Giuliani, Carcassi, Coste and Mertz). The Scruggs style and its banjo rolls are based upon and contemporary with parlor-style guitar.
Spanish-style (c.1845) / Size No.3 (3-17) (1859) guitars by C. F. Martin
Very first Size No.1 guitar with earliest X-Bracing (1842) by Martin & Schatz
c.f. Size No.0 (0-45) guitar played by Joan Baez
In the 2000s, the parlor guitar is enjoying a renaissance among players "who like their midrangery tone, historic vibe, and easy portability". Modern luthiers are making parlor guitars in a wide variety of tonewoods. Takamine Guitars produces one made of cedar and koa, with a preamp powered by a 12AU7, the first acoustic guitar with a tube preamp.Fylde Guitars produces the 'Single Malt Ariel' constructed from used whisky casks.