In 1945, the first formal women's barbershop organization, Sweet Adelines, was formed. In 1953 Sweet Adelines became an international organization, although it didn't change its name to Sweet Adelines International until 1991. The membership of nearly 25,000 women, all singing in English, includes choruses in most of the fifty United States as well as in Australia, Canada, England, Finland, Germany, Ireland, Japan, New Zealand, Scotland, Sweden, Wales and the Netherlands. Headquartered in Tulsa, Oklahoma, the organization encompasses more than 1,200 registered quartets and 600 choruses.