Music theory glossary

Definitions for the terms you’ll see in Chord Progressor. Use the search box to filter, but everything below is fully crawlable.

Roman numerals
Chord symbols relative to a key or scale. Uppercase = major, lowercase = minor, ° = diminished. Example in C major: I=C, ii=Dm, V=G, vi=Am. See common progressions.
ii‑V‑I
The most common functional cadence in major keys: ii (minor) → V (dominant) → I (tonic). It creates tension then resolution. See ii‑V‑I in all keys.
Tonnetz
A “tone network” that connects triads by shared tones. Neighbor moves P (Parallel), L (Leading‑tone exchange), and R (Relative) change only one note for smooth voice leading. See Tonnetz P/L/R guide.
Voice leading
The way individual chord tones move from one chord to the next. Good voice leading uses small steps and common tones. Tonnetz moves are built around minimal voice leading.
Diatonic
Belonging to the current scale. A diatonic progression uses only chords built from scale tones.
Borrowed chords
Chords taken from a parallel mode (same tonic, different scale). Example: in C major, borrowing iv (Fm) or bVII (Bb) from C minor. Also called modal mixture.
Mixing chords from parallel major/minor or other modes. It adds color while keeping the same tonic. See the “Try borrowing color” section in common progressions.
Secondary dominant
A dominant chord that resolves to something other than the tonic, temporarily tonicizing a new chord. Example in C major: D7 (V/V) resolves to G (V).
Pivot / modulation
Using a chord or short passage to move to a new key or scale. The app’s “Break out / pivot ideas” panel suggests practical nearby pivots.
Harmonic minor
Minor scale with a raised 7th: 1 2 b3 4 5 b6 7. Creates a strong dominant (V) in minor keys and yields several jazz modes. See harmonic minor modes.
Melodic minor (jazz minor)
Minor scale with raised 6th and 7th ascending: 1 2 b3 4 5 6 7. Used for modern minor harmony and altered dominants.
Bebop scale
An 8‑note scale that adds a passing tone so chord tones line up with downbeats in eighth‑note lines. See bebop scales guide.
Mode
A rotation of a parent scale with a distinct tonal center and characteristic intervals (Ionian, Dorian, Phrygian, etc.). Modes change the “flavor” of diatonic harmony.