Comhaltas Ceoltóirí Éireann (Gathering of Musicians in Ireland) is a large group involved in the preservation and promotion of Irish traditional music. They are a non-profit cultural movement with hundreds of local branches around the world, and as you can read in their history they have been working for the cause of Irish music since the middle of the last century (1951 to be precise). Comhaltas orgainises sessions, tours, classes as well as having an extensive Irish music archive. Website: Comhaltas