Tonal harmony is the foundation of most Western music, from Bach to jazz standards. At its core, it is a contract between composer and listener: if you follow its rules, the listener will always feel a sense of home—a tonal center called the tonic.
This sense of direction comes from how chords function and move within three main regions of tonality:
🎵 The Three Regions of Tonality
Every chord in tonal harmony has a function—a role it plays in the story of tension and release. These functions are grouped into three regions:
- Tonic (Home Base)
- The point of rest, least tension.
- Where the music feels settled.
- Example: C major in the key of C.
- Subdominant (The Journey)
- Transitional, moderate tension.
- Feels like moving “away from home.”
- Often described as “the mountain” in hymns, descending back to tonic.
- Dominant (The Tension)
- The highest level of tension.
- Creates expectation to return to tonic.
- Think of it as “the storm at sea” before returning to safe harbor.
🎼 The Circle of Fifths & The Harmony Map
The circle of fifths organizes all 12 tones and shows how chords relate to each other. By building triads on each scale degree in C major and C minor, we can classify every chord into one of the three regions.
- The V7 chord (G7 in C) always sits at “1 o’clock” on the map.
- The IV chord (F in C) is always at “11 o’clock.”
- The I chord (C) is always at “12 o’clock.”
This fixed placement means that no matter what key you’re in, functions always live in the same place.
🔀 Harmonic Progressions & Cadences
Music is a journey through this map. Each path between regions creates a recognizable cadence:
- V7 → I = Perfect Authentic Cadence (dominant to tonic).
- IV → I = Plagal Cadence (subdominant to tonic, “Amen” ending).
- ii → V7 = Subdominant to Dominant motion (the backbone of jazz progressions).
These are the main roads of tonal harmony. Exploring alternative “roads” is what reharmonization is all about.
🎶 A Real Example: “Sweet Home Alabama”
At first glance, the famous progression in Sweet Home Alabama seems to move from dominant → subdominant, which doesn’t establish the key strongly. This illustrates how important functional paths are in determining the real tonal center of a piece.
✅ Key Takeaways
- Tonal harmony organizes chords into three regions: tonic, subdominant, dominant.
- Each chord function has a fixed place on the circle of fifths map.
- Cadences are the most effective paths, guiding the listener’s sense of key.
- Understanding these paths is the first step toward reharmonization.
🛠 Practice It Yourself
Try mapping out all diatonic functions in every key. Start with C major and C minor, then expand. Use worksheets like the one in The Art of Reharmonization or explore interactively in Mapping Tonal Harmony Pro.
FAQ: Tonal Harmony
What is the difference between tonal and atonal harmony?
Tonal harmony is built around a tonic (home note or chord), while atonal harmony avoids a central key, giving equal weight to all pitches.
Why is tonal harmony important for musicians?
Tonal harmony provides structure, creates tension and release, and helps listeners follow the “story” of a piece. Without it, music can feel unstable or directionless.
How do I know if a chord belongs to tonic, subdominant, or dominant?
Classify by function: tonic chords provide rest, subdominant chords create transition, and dominant chords build tension. The circle of fifths (and tools like Mapping Tonal Harmony Pro) make this classification clearer.
Is tonal harmony only for classical music?
No. Jazz, pop, gospel, and rock all rely on tonal harmony. The cadences and functions are universal, though each genre applies them differently.
How do I practice tonal harmony?
Practice ii–V–I and IV–I cadences, analyze songs to identify functional regions, and use worksheets or apps to map chord functions in all keys.
👉 Want to dive deeper? Check out the full Art of Reharmonization book or explore tonal harmony interactively with Mapping Tonal Harmony Pro.
