Barbershop quartet Barbershop quartet 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
Barbershop music of the "revivalist" style are related to the desire to produce these ringing chords. Performance is a cappella to prevent the distracting introduction of equal-tempered intonation, and because listening to anything but the other three voices interferes with a performer's ability to tune with the precision required. Barbershop arrangements stress chords and chord progressions that favor "ringing", at the expense of suspended and diminished chords and other harmonic vocabulary of the ragtime and jazz forms. The dominant seventh-type chord is so important to barbershop harmony that it is called the "barbershop seventh". BHS arrangers believe that a song should contain