Passage II

Ringing in Harmony

Barbershop music—four voices singing in perfect harmony, without instrumental, accompaniment—can be traced back to late nineteenth-century African American barbershops. While waiting for a haircut, a patron might have improvised a melody. Two or three other customers would then harmonize higher or lower than the melody to create a song. [A] This pastime eventually became a widely known genre of music that's traditionally characterized by four men singing in red-and-white-striped suits and straw hats. [B]The songs usually have simple melodies and honeyed titles like “Let Me Call You Sweetheart” and “Sweet Adeline.” [C] Barbershop music has many distinctive qualities; however, enthusiasts say the music's true thrill, all in the acoustical effect called the ringing chord, or overtone. [D] Produced when all four voices perfectly combine to create the impression (hence the term "overtone") of a fifth note rising above the rest, the ringing chord is an acoustic phenomenon. Highly coveted, the ringing chord elicits what barbershoppers describe as emotional responses that are hair raising, skin prickling, and a tingling of the spine.

Quartets can only achieve this "angel's voice," nevertheless, with proper breath support and precise vocal technique. Collaboration is also crucial; each participant must listen to the others to sing flawlessly, tuned notes. When the singers each hold a different pitch-perfect note at the correct harmonic interval, the variations in frequencies in their voices overlaps. These audible frequencies above and below the four voices create the illusion of a fifth voice.

Few modern instruments can create this effect because of slight tuning imperfections. Keyboards, for example, are tuned such that a piece of music sounds equally good in any key, though this prevents frequencies from interacting and overlapping (necessary to "ring a chord"). Beyond honoring tradition, then: barbershoppers would be wary of adding instruments that might compromise the beloved ringing chord.