Four-part barbershop harmony can be sung in large groups, or in quartets, with one person singing each part. Most Sweet Adelines chapters have one or more quartets, some of whom sing solely to entertain audiences, and others who compete annually in the regional and international quartet contests, held concurrently with the chorus competitions. As in the chorus competitions, the quartet regional winners meet for international competition. The winners of the annual international quartet competition are crowned Queens of Harmony. They receive tiaras and membership in the Coronet Club, a select group of the best female barbershop singers in the world. Greater Harmony Chorus’ director, Bonnie McKibben, was crowned a Queen of Harmony in 1990 with her quartet Panache. Greater Harmony Chorus boasts quite a number of quartets, including B.L.A.K. Velvet, Bonnie’s current quartet. Some quartets’ members are all members of one chorus, and some have members representing two or more choruses.