Theory Topics
Fundamentals
  • Notation
  • Circle of Fifths
  • Major and Minor Scales
  • Intervals
  • Triads
Four-Part Voice Leading
  • Four-Part Voicing
  • Root Movement by Fifths
  • Root Movement by Thirds
  • Root Movement by Seconds
  • Voice Leading Inversions
  • Cadences
  • Natural Minor Scales
  • Harmonizing Melodies
  • Non-Harmonic Tones
Advanced Topics
  • Seventh Chords
  • Tonicization
  • Modulation
For extra practice and help, I recommend you try musictheory.net.