Half Step Theory

Explore scales and chords on the piano. Pick a type and a root note.

Scales

Major

The major scale (Ionian mode): seven notes following whole–whole–half–whole–whole–whole–half. The foundational scale of Western tonal music, with a bright, resolved character.

Natural Minor

The natural minor scale (Aeolian mode): whole–half–whole–whole–half–whole–whole. Darker than major, with a lowered 3rd, 6th, and 7th.

Harmonic Minor

Natural minor with a raised 7th, creating a strong leading tone back to the tonic. The augmented second between the 6th and 7th gives it an exotic, Middle-Eastern flavor.

Melodic Minor

Ascending melodic minor: natural minor with both the 6th and 7th raised. Smooths out the augmented second of harmonic minor while preserving the strong leading tone.

Major Pentatonic

Five-note scale built from the major scale by dropping the 4th and 7th — the two notes that produce tritones. Open, singable, and the foundation of folk music across many cultures.

Minor Pentatonic

Five-note scale built from natural minor by dropping the 2nd and 6th. The backbone of blues, rock, and most pop guitar solos.

Chords

Major

The major triad: root, major third, perfect fifth. Bright and resolved.

Minor(m)

The minor triad: root, minor third, perfect fifth. Darker counterpart to major.

Diminished(°)

Root, minor third, diminished fifth. Tense and unstable; wants to resolve.

Augmented(+)

Root, major third, augmented fifth. Symmetric and ambiguous — every note can act as the root.

Major 7(maj7)

Major triad with an added major seventh. Lush and jazzy.

Minor 7(m7)

Minor triad with an added minor seventh. The workhorse minor chord of jazz and pop.

Dominant 7(7)

Major triad with an added minor seventh. The tension chord that resolves home — the V7 of tonal music.

Half-diminished 7(m7♭5)

Diminished triad with an added minor seventh. Also written ⌀7. The ii of minor-key ii–V–i progressions.

Minor-major 7(m(maj7))

Minor triad with a major seventh on top. Tense and cinematic — the tonic chord of harmonic and melodic minor.

Augmented major 7(maj7♯5)

Augmented triad with a major seventh. The III chord in harmonic and melodic minor — luminous and unmoored.

Diminished 7(°7)

Diminished triad with a doubly-diminished seventh — every interval is a minor third. Symmetric; any inversion is another diminished 7.