Barbershop music, with its close, unaccompanied four-part harmonies and ringing chords, is a uniquely American folk art. It evolved in much the same way as other forms of vocal music. Although no one can say exactly when or where barbershop music began, the growth of the tradition was certainly aided between the 1860s and 1920s by the types of songs popular at the time - songs characterized by sentimental lyrics and uncomplicated melodies that could be harmonized with a variety of four-part chords.

In the early years of American barbershop music, singers improvised harmonies. When the printing press was adapted to produce musical notation, there was further advancement of the barbershop idiom. Many early pieces of sheet music were printed with standard vocal line and piano accompaniment, and with an additional quartet arrangement on the final page.

At the turn of the century amateur singers, usually men, could often be heard singing improvised barbershop harmony at parties and picnics. Minstrel shows also featured barbershop quartets, who sang in front of the curtain as an "olio" act while performers and stage hands prepared for the next act. It was convenient to use a quartet for this purpose, since no props or instruments were required.

Barbershop harmony's four voice parts are still called by their traditional names - tenor, lead, baritone and bass - whether referring to men's or women's vocal groups. One of the distinctive qualities of barbershop harmony is that the melody, sung by the lead voice, is below the tenor harmony. This follows the pattern of many early American hymns written for men and women, with the melody in the male tenor voice and the women singing harmony above. The barbershop harmony of today is a highly stylized art form requiring the same high degree of singing skill as other types of choral music.

As the popularity of barbershop harmony has grown, so has the type of participation. Barbershop singing is no longer restricted to male quartets; there are many women's quartets, and both men's and women's choruses now enjoy this unique art form. Choruses ranging in size from 15 to 150 or more members have found this singing style a challenging and exciting musical experience.