So what exactly is barbershop? The hallmark of the style is 4-part harmony arranged such that the melody is surrounded above and below by the three harmony parts. It is sung unaccompanied by musical instruments. The lead sings the melody with the tenor singing above the lead and the bass below. The baritone sings a compromise part unique to barbershop, sometimes above the lead and sometimes below. Placing the melody in a middle voice as opposed to either the top or the bottom of the chord is what distinguishes barbershop from other forms of vocal harmony. Having four parts from which to choose makes barbershop accessible to the average singer. From the highest tenor to the lowest bass, the style offers everyone the opportunity to sing, whatever their vocal range.

Many different types of music are adaptable to the barbershop style, from hymns and gospel through to doo-wop, swing and show tunes. While the occasional popular song can be found in a barbershop repertoire, the style is best suited to songs from an earlier era -- an era when songwriters tended to write lyrics that told a story, with melodies that invited harmony, sung from the heart. These familiar songs were written mostly between 1900 and 1960.