In 2017 I started a video instruction series focusing on music theory, with the intent to provide not only an entry-point into music theory, but to deliver the deep university-level music theory content that many students do not have cheap access to due to their circumstances. Below you will find the complete playlist linked as well as each individual topic.
Part 2: The Overtone (Harmonic) Series
Part 3: Harmonic Pitch Collections
Part 4: The Organization of Time and Rhythm
Part 5: Intervals as Just Ratios
Part 6: The History and Purpose of Music Notation
Part 8: Chords – Triads in the Tonal System (introduction)
Supplement: Moving Beyond Standard Triads
Part 11: Keys and Key Signatures