Mission Viejo Chapter of Sweet Adelines International. The Mission Viejo Chorus was chartered in 1969 as a part of Sweet Adelines International to encourage and promote the American folk art of four-part harmony barbershop style, without instrumental accompaniment. We are a diverse group of women from all walks of life, made up of all ages, ethnicities, religions, and sizes. We range in age from the early 20s to the 70s. We are professionals, homemakers, caretakers, and retirees. We live all over Orange County, and originate from all over the country and world. What we all have in common, is a love for singing and sharing four-part harmony, and for developing close friendships that last a lifetime.