Related Keys
Keys are connected to other keys through four relationships: relative (same notes, different tonic), parallel (same root, different mode), dominant (a 5th up), and subdominant (a 5th down). These relationships explain why certain key changes sound smooth.
The Four Key Relationships
| Relationship | How to Find | Shared Notes | Effect |
|---|---|---|---|
| Relative Minor/Major | Down 3 semitones for minor | All 7 notes | Smoothest key change possible |
| Parallel Major/Minor | Same root, opposite mode | 4 of 7 notes | Same root, different mood |
| Dominant | Up a perfect 5th | 6 of 7 notes | Very smooth, one note different |
| Subdominant | Down a perfect 5th | 6 of 7 notes | Equally smooth, opposite direction |
Why Relationships Matter
The relative relationship is the closest possible: C major and A minor share every note. The only difference is which note feels like "home." This is why relative major-minor switches flow so naturally in songs.
The parallel relationship shares the same root but changes the mode: C major and C minor. Three notes change, making it more dramatic. Borrowed chords — like the iv chord in "Creep" by Radiohead — come from the parallel minor, adding emotional color to a major-key song.
The dominant and subdominant keys differ by only one note each. Moving to the dominant key (C major to G major) feels like a natural brightening. Most modulations in popular music move between these closely related keys because the shared notes create smooth transitions.
In ChordColor
Key pages display all four related keys as navigation links, letting you explore harmonic neighborhoods. The related keys are computed automatically for any key you select.