Barbershop Quartet Day
…barbershop harmony is a style of unaccompanied singing with three voices harmonizing to the melody. The lead usually sings the melody, with the tenor harmonizing above the lead. The bass sings the lowest harmonizing notes and the baritone provides in-between notes, either above or below the lead to make chords (specifically, dominant-type or "barbershop" sevenths) that give barbershop its distinctive, "full" sound*
I’m not quite sure if this video clip qualifies as a "Barbershop Quartet," but this is just too amazing not to feature! Enjoy!
*source: Barbershop Harmony Society