Music Theory Societies

• Harvard's Society for Music Theory (SMT) page now lets you search the SMT database from the web. Be sure to check out the SMT's new Virtual Poster Sessions.
• IU School of Music Graduate Theory Association
• Rocky Mountain Society for Music Theory
• Music Theory Midwest

Journals and Magazines

• Journal of Music Theory (JMT)
• Music Theory Online (MTO)
• Indiana Theory Review (ITR)
• Computer Music Journal
• Dutch Journal of Music Theory / Tijdschrift voor Muziektheorie

Composition

• ARCANA (Artist Research, Composers' Aid & Network Access) Offers a great glimpse of German contemporary composers and music.
• Gems Series Collection of Essays on composition

Education

• Resources for Music Educators
• Larry Newman's Music Education Online
• Music Theory at Indiana University
• Here's an impressive Ph.D. proposal by Alan Ruttenberg (in color).
• Teoria.com -- Practical Music Theory in Spanish and English
• Tim Smith has an excellent Bach page with analyses of canons and fugues

Reference

• All about Set Theory by yours truly, a companion page to my Set Theory calculator java applet
• Can you believe it? There's a Lerdahl and Jackendoff page!
• Music Theory Online - Dissertation Index
• Rhythm and Meter Bibliographic Glossary
• Semiotics for Beginners by Daniel Chandler. Geared towards students of film and television, but still very useful for the basics of semiotics.
• Music Library Association (MLA) Clearinghouse
• Lexicon musicum Latinum, information about the manuscripts, new editions, articles, and books of medieval music theory (German and English)
• Thesaurus Musicarum Latinarum (Our very own)
• Thesaurus Musicarum Italicarum (TMI) Utrecht University
• Tuning & temperament bibliography
• International Conference on New Musical Notation
• THEMA stands for (Music) THEory of the Middle Ages
• Temperaments -- includes a nifty Java applet that lets you compare the frequencies in different types of tuning
• Theoria: Historical Aspects of Music Theory (University of North Texas)

Other

• Music, Mind, and Machine: Computational Modeling of Musical Knowledge and Cognition -- They wired a high-heel shoe to a computer and taught it to tap along...
• The Gregorian chant home page, which includes relevant links to the fields of Linguistics and Cognition
• Música e Artistas -- Destaques do meio musical, Eventos, Músicas MIDI, Opiniues e debates, Informagues gerais... lots of great Brazilian music resources, including MIDI files of Brazilian music. (Portugese and English)

Humor

• The Texas Institute of Theory. Get ready to laugh...
• 75 signs you might be a theory geek