The American Theatre Organ Society (ATOS) is an international non-profit organization comprised of worldwide volunteer members who are committed to helping preserve and perpetuate the musical theatre pipe organ heritage that began in the early 20th century. Membership is made up of musicians, technicians, hobbyists, educators, and others who enjoy the music of the theatre pipe organ. Founded in 1955, the ATOS consists of regional member-chapters and is led by democratically elected leaders. It operates in accordance with 501 (c) (3) regulations. ATOS expects to participate in growing the number of active theatre organs, expanding public awareness of this art form, and bringing a new generation of theatre organ audiences, supporters, technicians and artists into the fold of a flourishing ATOS. The efforts are expected to facilitate a thriving theatre organ presence worldwide.