Barbershop arranging

The Barbershop Harmony Society (BHS) and Sweet Adelines International (SAI) have prescribed rules that dictate what is an acceptable arrangement, particularly with regard to singing in competition.

[citation needed] The following 2 paragraphs from the BHS indicate technical requirements of a barbershop arrangement for use in a BHS contest: Barbershop harmony is a style of unaccompanied vocal music characterized by consonant four-part chords for every melody note in a predominantly homophonic texture.

The melody is not sung by the tenor or bass, except for an infrequent note or two to avoid awkward voice leading, in tags or codas, or when some appropriate embellishing effect can be created.

Barbershop music features songs with understandable lyrics and easily singable melodies, whose tones clearly define a tonal center and imply major and minor chords and barbershop (dominant and secondary dominant) seventh chords that resolve primarily around the circle of fifths, while making frequent use of other resolutions.

A music category judge can assess an arrangement by ear or eye to test whether it is 'barbershop', and hence valid for use in competition.