What is Barbershop?
Definition of Babershop Harmony
(Adopted by the International Board at the 1977 convention. Appears officially as the Foreword of the Contest and Judging Handbook, published by SPEBSQSA, inc.)
Barbershop harmony is a style of unaccompanied vocal music characterized by consonant four-part chords for every melody note. Occasional brief passages may be sung by fewer than four voice-parts.
The voice-parts are called tenor, lead, baritone and bass. The melody is consistently sung by the lead, with the tenor harmonizing above the melody, the bass singing the lowest harmonizing notes below the melody, and the baritone completing the chord either above or below the melody. The melody may be sung occasionally by the bass, but not by the tenor, except for an infrequent note or two to avoid awkward voice leading, and in introductions or tags (codas).
Barbershop music features major and minor chords and barbershop (dominant-type) seventh chords, resolving primarily on the Circle of Fifths. Sixth, ninth, and Major seventh chords are avoided except where demanded by the melody, while chords containing the minor second interval are not used. The basic harmonization may be embellished with additional chord progressions to provide harmonic interest and rhythmic momentum, to carry over between phrases, or to introduce or close the song effectively.
Barbershop interpretive style permits relatively wide liberties in the treatment of note values - staying within proper musical form - and uses changes in tempo and volume to more effectively create a mood and tell a story artistically.
Relative to an established sense of tonality, the melody line and the harmony parts are enharmonically adjusted in pitch to produce an optimum consonant sound. The resulting pitch relationships are often considerably at variance with those defined by the equal temperament of fixed-pitched instruments. Singers strive to use similar word sounds in good quality. All this together with the use of optimum volume relationships by each of the four harmonics (overtones) produces the unique full or "expanded" sound characteristic of barbershop harmony.