Calendar for New Music - New York City listing of avant-garde, experimental jazz, and new music events.
Electronic Music Foundation - Information and materials relating to the history and current practice of electronic music. This organization also hosts an experimental music calendar.
Experimental Sound Studio - A non-profit organization founded in 1986 for the production and promotion of innovative approaches to the sonic arts.
Lampo - A Chicago-based nonprofit organization that presents experimental music and intermedia events. With current schedule, past events archive and mailing list.
Mechanical Music Digest - Mailing list that discusses mechanical musical instruments. Of interest to experimental music fans are the threads on Conlon Nancarrow and others.
SoniCabal - A freeform collective of Seattle-area rule bending musicians and sound manipulators. With performance calendar, pictures, member profiles, and links.
SoundList - Website and email list for announcements of experimental music, free improvisation and sound art events in the Toronto area.
Vorgon Massive - Long Island experimental music collective site, maintained by Droog.