What is a Harmonic Sequence?
A harmonic sequence is a repetition of a chord progression pattern that is transposed up or down by a consistent interval. Unlike melodic sequences (which deal with single-note patterns), harmonic sequences involve chord progressions and are crucial in tonal music.
Types of Harmonic Sequences
1. Descending Fifth (Circle Progression) Sequence
- Chords move down by a fifth (or up by a fourth) in a cycle.
- Common in Baroque, Classical, and Pop music.
- Example: C → F → Bdim → Em → Am → Dm → G → C (Classical circle progression).
2. Ascending Fifth Sequence
- Chords move up by a fifth (or down by a fourth).
- Less common but used for modulation or tension-building.
- Example: C → G → D → A → E → B (often leads to key changes).
3. Pachelbel Sequence (Descending Thirds + Stepwise Bass)
- Made famous by Pachelbel’s Canon in D.
- Bass moves down a third, then up a step in a repeating pattern.
- Example: D → A → Bm → F#m → G → D → G → A (I-V-vi-iii-IV-I-IV-V).
4. Chromatic Sequence
- Chords move by chromatic (half-step) shifts.
- Creates dramatic or unstable harmonic motion.
- Example: Cm → C#dim → Dm → D#dim → Em (common in Romantic music).
How to Identify a Harmonic Sequence
✔ Look for repeating chord patterns shifted up/down.
✔ Check if root movements follow a consistent interval (e.g., fifths, thirds).
✔ Listen for cyclical progressions (e.g., Pachelbel’s Canon).
Why Are Harmonic Sequences Important in AP Music?
- Helps in analyzing chord progressions in classical and pop music.
- Essential for composition and modulation techniques.
- Frequently tested in AP Music Theory exams (e.g., identifying sequences in Bach chorales).
Examples in Music
- Pachelbel – “Canon in D” (Descending thirds sequence).
- Beethoven – “Sonata Pathétique” (Uses descending fifths).
- Coldplay – “Clocks” (Modern pop use of harmonic sequences).
Conclusion
Mastering harmonic sequences is key for AP Music Theory students, composers, and performers. Whether it’s the circle of fifths, Pachelbel sequences, or chromatic shifts, understanding these patterns enhances music analysis and creativity.
Find us on Facebook
Study AP Music