Atonal Set Calculator - Interactive atonal set calculator for pitch class sets and twelve-tone rows. Enter one or two sets and find normal order, prime form, Forte number, interval vector, and symmetry.
Auto-Transposer - Transposes all twelve major keys of chord progressions.
A Beginner's Guide to Modal Harmony - A concise explanation of the Gregorian and Renaissance modes and their development in the Common Practice era.
Bimodalism - A contemporary alternative to atonal styles of composition.
Essentials of Music Theory - Summarizes entry-level music theory through advanced topics. Includes beginners' drills.
The Fugue - An outline of the fundamentals of a fugue based on Hugo Norden's "Foundation Studies in Fugue."
Fugue No. 17: A-Flat Major - Introduction to the essential concepts of Schenkerian analysis applied to the Ab Major fugue of Bach's Well-Tempered Clavier, Book I
Harmonic Bindings - A paper about the unification of Janecek's theory of imaginary tones with the two Risinger's principles of functional relations.
Harmony.org.uk - By Tom Sutcliffe. Aims to help students of music theory understand the role of chord progressions in musical structures. Site includes animated demos.
Interactive Circle of Fifths - A free music theory tool designed to help musicians interpret chord progressions, easily transpose music to a different key, compose new music, and understand key signatures, scales, and modes.
Interval and Chord Ear-Training - This site drills ear-training (aural skills), focusing on the aural recognition of musical sounds, including intervals and chords.
Modes and Scales in Indian Music - A historical look at concepts of Indian scales and modes comparing North and South Indian approaches.
Music Acoustics - The science of music. Explanations of how musical instruments work via waves and frequency modulation.
Music Theory - A guide to music theory that including chords, scales, music notation and other music theory topics. Has weblog format; includes links as well.
Music Theory - Covers intermediate and slightly advanced topics in tonal music theory.
Music Theory Help Site - Intermediate music theory help covering basics through beginning formal analysis and counterpoint.
Music Theory Instruction - Online instruction for all musicians beginner or advanced. Covers scales, chordal theory, progression theory, modes and foreign scales.
Music Theory Society of New York State - Provides a forum for the exchange of information and to promote music theory as a scholarly and pedagogical discipline. Site also contains membership and scholarship information as well as open calls for papers.
Music Worksheets - Downloadable worksheets for elementary and middle school students.
The Musical Octave - Thomas Váczy Hightower's study of musical scales. Discuses the meta-physical properties of music and the creation of musical scales from an acoustic and mathematical perspective.
Nuottila - Online ear training fundamentals site. [Requires Java]
Pattern Thinking in Music - Offers visual aid to recognizing musical patterns occurring in melody, harmony and rhythm. Provides online demonstration; requires download.
Polytempo Music Articles - Articles by John Greschak. Includes an annotated bibliography of polytempo music.
Rhythm Exercises - Notation for drills, rudiments and etudes for practicing rhythm.
Ricci Adams' Musictheory.net - Includes introductory and intermediate music theory lessons, ear trainers, and books.
SchenkerGuide - An introduction to Schenkerian analysis for undergraduate music students. Includes background, working method, glossary and bibliography.
Schoen Musical Notation - Julius Schoens alternative to traditional musical notation, has music notation documents, reference, and discussion.
Skytopia: Music and Art Aesthetics - Author's overview of how every piece of music, every sound, and every picture can be rated on its own merits outside (as well as inside) human opinion.
Solomon's Music Resources - Resources for composers, music theorists, and researchers of music, with sound files, papers and compositions.
Star Theory - Free preparatory syllabus in music theory and orchestration.
Technical Committee on Musical Acoustics - A group within the Acoustical Society of America, that concerns itself with the application of science and technology to the field of music. Contains members, a list of papers, acousticians and links.
Teoria - Includes software, books, exercises, and links.
Theory on the Web - Intermediate music theory review for college students.
The Tonal Centre - Interactive site for music composers and theorists which explains and demonstrates some of the key concepts of tonality; including chords, scales, cadences, and modulation.
Tonality Guide - Fundamentals of tonality and music theory created as an online teaching tool with written and aural examples.
8-Tone Quarto-Modes Concept - Information with mp3 files, an introduction to the "diminished-major" and its applications.
VCU Music Theory Resources - Music theory and ear training resources from Virginia Commonwealth University.