Barbershop quartet

A barbershop quartet is a group of four singers who sing music in the barbershop style, characterized by four-part harmony without instrumental accompaniment, or a cappella. The four voices are: the lead, the vocal part which typically carries the melody; a bass, the part which provides the bass line to the melody; a tenor, the part which harmonizes above the lead; and a baritone, the part that frequently completes the chord. The baritone normally sings just below the lead singer, sometimes just above as the harmony requires. Barbershop music is typified by close harmony— the upper three voices generally remain within one octave of each other.

While the traditional barbershop quartet included only male singers, contemporary quartets can include any gender combination. All-female barbershop quartets were often called beauty shop quartets, a term that has fallen out of favor. The voice parts for women's and mixed barbershop groups use the same names as those for male groups since the roles perform similar functions in the quartet although the vocal ranges may be different.

While the regional origins of barbershop quartet singing are not wholly agreed upon,^[1] current organizations that promote the style typify it as an "old American institution."^[2] While the style is most popular in the United States, barbershop organizations exist in the United Kingdom,^[3] The Netherlands, Germany, Ireland, South Africa, Finland, Sweden, Denmark, New Zealand, Australia, and Canada.^[4]

Barbershop quartets have been featured in popular culture in musical theater productions such as The Music Man, or lampooned in television series such as The Simpsons and Family Guy.