By Nick Marshall. The Society for Music Theory - Established in 1977 in order to promote music theory as both a scholarly and a pedagogical discipline. Star Theory - Free preparatory syllabus in music theory and orchestration. Syntactic Structures in Music - By Tom Sutcliffe. Aims to help students of music theory understand the role of chord progressions in musical structures.
Site includes animated demos.
Texas Institute of Theory - Devoted entirely to the promulgation of music theory in the Western European tradition. WholeARTS Music Conservatory - Introductory dialogue for courses in music theory and composition.