What is the minor third interval?
The minor third spans three semitones and forms the emotional backbone of minor harmony. When you play a note and count upward through three half steps, the darker, introspective quality you hear defines countless minor chords, blues melodies, and melancholic themes across every musical genre. Unlike its brighter sibling the major third, the minor third creates a sound that composers instinctively reach for when expressing longing, mystery, or depth.
In notation, the minor third appears as three letter names spanning two staff positions—C to E♭, D to F, or A to C. This interval sits at the heart of every minor triad, anchoring the middle note between the root and the perfect fifth. Whether you encounter it in a natural minor scale, a jazz chord voicing, or a rock power progression, the minor third instantly shifts the harmonic colour from major brightness to minor introspection.
Theory at a glance
Music theory treats the minor third as the defining interval that separates major from minor sonorities. Stack a minor third above a root note, add a perfect fifth, and you construct a minor triad—the fundamental building block of minor tonality. In the harmonic minor scale, the minor third between the tonic and the third scale degree establishes the minor quality while the raised seventh creates the characteristic leading tone. Melodic minor scales preserve this interval in their ascending and descending forms, cementing the minor third as an indispensable colour in tonal harmony.
The interval also appears between adjacent chord tones in extended harmonies. Jazz musicians layer minor thirds vertically to create diminished seventh chords, where four stacked minor thirds span an entire octave. Blues players bend notes upward from the minor third toward the major third, exploiting the expressive tension between these two intervallic flavours. Understanding the minor third unlocks these advanced techniques and deepens your grasp of chord construction across styles.
- Semitone distance: three half steps (0 → 3)
- Scale-degree formula: root to ♭3 in minor keys
- Chord role: defines minor triads and minor seventh chords
- Inversion: inverts to a major sixth (nine semitones)
How it sounds
The minor third sounds darker and more introspective than the major third, yet remains perfectly consonant and stable. Train your ear by singing the opening phrase of "Greensleeves," where the melody drops a minor third on the word "were." The opening bass line of Beethoven's Fifth Symphony also outlines a minor third descent, giving that iconic motif its dramatic weight. Alternatively, hum the first two syllables of "Georgia On My Mind"—the upward leap from "Geor—" to "—gia" traces a minor third that captures the song's wistful character.
When you play a minor third against a sustained root note, you hear a mellow blend that lacks the brightness of a major chord but avoids the harshness of a tritone. This quality makes the minor third ideal for introspective ballads, moody film scores, and the plaintive melodies found in folk traditions worldwide. Practicing the interval in both melodic (one note after another) and harmonic (simultaneously) contexts helps you internalize its characteristic sound and emotional impact.
Where you'll hear it
The minor third appears everywhere in Western music. Every minor chord— whether a simple A minor triad, an E minor seventh, or a complex minor ninth voicing—contains a minor third between its root and third. The interval also drives the sound of blues music, where guitarists and pianists bend or alternate between the minor third and major third to create that signature blue-note ambiguity. In jazz, minor thirds stack inside diminished chords and guide voice leading through ii–V–I progressions in minor keys.
Classical composers exploit the minor third to establish minor tonality in symphonies, concertos, and chamber works. Film and game composers layer minor thirds in orchestral strings to evoke mystery, sadness, or suspense. Even pop and rock songs built around minor progressions—think "Stairway to Heaven" or "Losing My Religion"—rely on the minor third to anchor their harmonic identity. Whether you're analyzing a Dorian mode melody or a contemporary R&B groove, the minor third is never far from the action.
Practice ideas
Start by playing every minor third on the keyboard, beginning with C to E♭, then moving chromatically upward through all twelve starting notes. Sing each interval as you play it, matching the pitch to lock the sound into your ear. Next, build minor triads by adding a perfect fifth above each minor third you've practiced—this reinforces how the minor third functions as the defining colour inside minor chords.
For melodic practice, improvise short phrases over a repeating A minor chord, deliberately targeting the minor third (C) as a resting point. Try bending notes or sliding into the minor third from a semitone below to mimic blues phrasing. Finally, transcribe melodies from songs you love that feature prominent minor thirds—singing and playing these lines by ear will deepen your connection to the interval's expressive power and prepare you to use it confidently in your own compositions and improvisations.