Professional Organizations
The American Guild of Organists
Organ Historical Society
The Hymn Society
The Organ Club
Royal Canadian College of Organists
Royal College of Organists
American Choral Directors Association
Choristers Guild
Friends of the Wanamaker Organ
The Guild of Carillonneurs in North America
Handbell Musicians of America
American Theatre Organ Society
National Association for Music Education

Pipe Organ Building Resources
American Institute of Organbuilders
Associated Pipe Organ Builders of America

Religious Affiliated Organizations
Association of Anglican Musicians
Association of Lutheran Musicians
Church Music Association of America
Fellowship of United Methodists in Music and Worship Arts
National Association of Pastoral Musicians
Presbyterian Association of Musicians
Unitarian Universalist Musicians Network
United Church of Christ Musicians Association

Interesting sites
Musical Glossary for Kids
https://www.playgroundequipment.com/a-playground-for-music-and-education-theory/