Dimitri Tymoczko (http://dmitri.mycpanel.princeton.edu/ChordGeometries.html) Devoted to providing pictorial and geometric representations of chords and harmonic structures, this Princeton University theorist and composer has made great strides in having musical harmony considered by scientists and other non-musicians as an advanced structural system worthy of study. His animations, all of the Chopin E minor Prelude, introduce listeners to things about harmony in a structural way, both aurally and visually. This website is a good resource for visual learners and those interested in further harmonic education and exploration.

Harmony.org.uk (http://www.harmony.org.uk/demo_menu.htm) With animations of tonal harmonic structures from Haydn, Mozart, and Bach, this website provides basic reinforcement of music vocabulary and walk students through the harmonic progression as they hear the music play. This works well for students who want a step-by-step guide but also need aural and visual information to more fully realize musical concepts.