We're beginning our list. Please let us know if you have others to add!
Performing Arts EncyclopediaNational Association for Music Education StandardsChoral Public Domain LibraryThe Hymn SocietyOremus HymnalCyberhymnalThe Ethereal LibraryThe Presbyterian Hymnal OnlineChoral WikkiHear the Choirs SingMudcat CafePhil TulgaMusic Blog CatalogOnline Musical Quiz Huge Collection of Links
Bluegrass LyricsSong Tracker sheet (PDF file -- fits in your planner)Guitar chord planner page Music papers to printMusic paper for your plannerMusic classroom resourcesMusic physicsLessons on the math of stringed instrumentsLessons on ostinatiHomemade percussion