The American Guild of Organists (AGO) is the national professional association serving the organ and choral music fields. The Guild serves approximately 20,000 members throughout the United States, Asia, Australia, and Europe. Founded in 1896 as both an educational and service organization, the Guild, headquartered in New York City, seeks to set and maintain high musical standards and to promote the understanding and appreciation of all aspects of organ and choral music. Each AGO year runs from October 1 to September 30. In any given year, a chapter may host concerts, educational events and social gatherings, have regular monthly meetings, and participate in either a regional or a national convention.
The Association of Organists of Southern California was established in 1908 and in 1910, it became the Southern California Chapter of the American Guild of Organists. As other chapters were founded around California, the chapter changed its name to the Los Angeles Chapter. In 1936, the Pasadena Chapter split off from the Los Angeles one; in 1999, they recombined.