What distinguishes barbershop music from other music forms?
Barbershop music is characterized by tight four-part a capella harmonies. The four parts are Tenor, Lead, Bass, and Baritone. If you hear a fifth part or feel a shiver down your spine, the group has produced a ringing chord. That is, they got everything just right so that the fifth part mysteriously appears. This happens because each note in the chord is adjusted slightly from an even-tempered scale to a pythagorean scale so that the overtones reinforce one another to the point where they become easily audible. True barbershop harmony emphasizes Major triads (1-3-5-1) and Dominant 7th (1-3-5-7♭) chords. These most easily produce the ring that is so coveted. While the old standards are always popular, many pop tunes are adapted to the barbershop style with pleasing results.
