The tenor is the highest of the four parts and is sung above the melody. By lore, baritones are the butts of barbershop humor. The bass is the lowest part, providing the harmonic foundation. Bass singers should have a rich, mellow voice and be able to sing the E flat below middle C easily. Barbershoppers use many musical embellishments, such as swipes and tags.
Swipes are progressions of two or more chords sung on a single word or syllable.
Tags are short songs or beautiful endings to songs, the final six or eight measures that cap the performance. A distinctive feature of barbershop harmony is the phenomenon of expanded sound, called ringing a chord. Singers create it when the four voices reinforce each other to produce audible overtones and undertones. Many of the people who sing in local groups are members of one of three international organizations that help preserve and promote this music. Women barbershop singers can join the Sweet Adelines International, with 30,000 members, or Harmony Inc., with 2,800 women concentrated in the northern and eastern regions of North America.