Topics

SeeChord can help to visualise the structure of any harmonic sequence, however random it may seem at first.  The following topics are a good place to start:
Introduction
Basic harmonic movement
Structure
Major and minor keys
Connectors
Chords
Modulation
Relative majors and minors
Interpretation
Chord progressions
Song construction
Blues
Cadences
Modes
Harmonization
Substitutions
Advanced chords
Ambiguous chords