A barbershop quartet is a group of four singers who sing music in the barbershop genre of singing, which uses four-part harmony without accompaniment by any instruments such as piano, a style called a cappella. It consists of a lead, the vocal part which generally carries the tune/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 completes the chord with the note not being sung by the lead, bass, or tenor singers. The baritone can sing either above or below the lead singer.
Quartets can be male or female, but are generally not mixed male and female. A female barbershop quartet may be referred to as a Sweet Adelines quartet (taking the title from the barbershop classic "Sweet Adeline"), and the vocal parts have the same labels, since the roles perform similar functions in the quartet even though the vocal ranges are different. Most barbershop quartets are male.
Barbershop singing originated in the late 1800s and early 1900s of America, a hybrid of both black and white expressive cultural forms at the time. The African-American influence is sometimes overlooked, although these quartets had a very formative role in the development of this style of singing. Popularity of the style faded in the 1920s and was revived in the mid-20th century with help by the Society for Preservation and Encouragement of Barber Shop Quartet Singing in America, founded in 1938. Some researchers view the style as an invented tradition based on the early musical features and the society's application of the barbershop chord with its contests and rules.
As a general rule, barbershop quartets use a TTBB (tenor--tenor--baritone--bass) arrangement, with the second tenor on lead vocal.
The tenor generally harmonizes above the lead, making the part the highest in the quartet. So as not to overpower the lead singer, who carries the tune, the part is often sung in falsetto, which is of a softer quality than singing in the modal register, though some quartets do make use of tenors with a softer full voice quality. Notable examples of barbershop quartets which made use of the full-voiced tenor include The Buffalo Bills and Boston Common.
The range of a tenor in barbershop music does not necessarily closely correspond to that of a tenor's range in Classical repertoire, often being more in the range of the classical countertenor range.
Media related to Barbershop quartets at Wikimedia Commons