What is the major sixth interval?
The major sixth measures nine semitones from its root, landing one semitone above the minor sixth. When you invert it, the interval flips into a minor third—three semitones downward instead of nine upward. This mathematical relationship means that whenever you voice a major sixth ascending, you simultaneously hint at the intimate character of a minor third descending, creating harmonic flexibility that enriches both chordal voicings and melodic lines.
In practical terms, if you start on C and count up nine semitones, you arrive at A. That C to A leap captures the essence of the major sixth: open enough to feel spacious, yet close enough to remain singable and lyrical. Composers favor this interval when they want to convey nostalgia, tender affection, or uplifting optimism, making it a cornerstone of major scale melodies and romantic ballads alike.
Theory at a glance
In tonal harmony the major sixth typically appears as the interval between the root and sixth degree of a major scale. For example, in C major the interval from C up to A forms a major sixth that reinforces the scale's bright, stable character. Because the interval inverts to a minor third, voice-leading techniques often pair these two sounds: a melody rising by major sixth can resolve downward by minor third, or vice versa, creating smooth contrary motion that composers use to navigate between major triads and their relative minors.
The major sixth also plays a structural role in major sixth chords, where it sits atop the root, third, and fifth to add a sweet, jazzy color. You'll find this voicing throughout swing standards and bossa nova tunes, where the added sixth softens the triad without introducing the tension of a seventh. In modal contexts, the interval helps define Dorian mode by pairing a natural sixth with a minor third, blending minor tonality with a brighter, more open sound.
- Semitone distance: nine steps (0 → 9)
- Inversion: flips to a minor third (three semitones)
- Scale context: appears as natural 6 in major keys, ♯6 in harmonic minor
- Harmonic role: defines major sixth chords and enriches pentatonic scales
How it sounds
The major sixth feels warm, nostalgic, and gently uplifting, striking a balance between the bright openness of a perfect fifth and the intimate sweetness of a major third. Train your ear by singing the opening phrase of "My Bonnie Lies Over the Ocean" or the first two notes of the famous NBC chimes (the C to A leap), both of which ascend by major sixth. Playing the interval melodically over a sustained root note helps you internalize its lyrical character, while blocking it harmonically reveals the rich, romantic quality that makes it perfect for expressive ballads and sentimental themes.
Because the major sixth inverts to a minor third, you can also explore its sound by playing a minor third downward from any note: the resulting character feels more intimate yet retains the same intervallic distance. This dual perspective—ascending warmth versus descending tenderness—explains why the major sixth appears so frequently in vocal melodies and string arrangements, where composers exploit both its soaring quality and its gentle inversions to craft emotionally resonant lines.
Where you'll hear it
Jazz pianists and arrangers weave the major sixth into extended voicings—such as major sixth chords and ninth chords—to add color without clash. Standards like "Take the A Train" and "Fly Me to the Moon" showcase the interval's ability to soften cadences and create smooth voice leading between chords. Film composers layer major sixths over orchestral strings to evoke nostalgia or heartfelt sincerity, while pop ballads often outline the interval in vocal melodies to underscore romantic optimism and emotional warmth.
You'll also find the major sixth anchoring melodic phrases in major pentatonic scales, where the absence of semitone dissonances highlights the interval's open, lyrical character. In modal jazz and fusion, the major sixth appears in Dorian mode and Mixolydian mode, blending bright tonality with subtle tension that keeps harmonic progressions engaging and forward-moving.
Practice ideas
Start by locating every major sixth on the keyboard: pick a root note, count up nine semitones, and play the pair blocked and broken in both hands. Next, practice singing the interval against a drone or backing track, then resolve it upward by semitone to hear how it expands into a minor seventh or downward by whole tone to settle on a perfect fifth. Finally, improvise short phrases over a C major vamp, deliberately emphasizing the sixth degree to feel how the major sixth colors diatonic harmony and connects smoothly to surrounding chord tones.
To deepen your understanding of the inversion relationship, practice playing ascending major sixths followed immediately by descending minor thirds. For example, play C up to A, then A down to F♯, listening for how the intervallic quality shifts while the mathematical distance remains constant. This exercise sharpens your ear for voice-leading possibilities and helps you recognize the major sixth in both melodic leaps and harmonic contexts, whether you're analyzing major sixth chords or improvising over pentatonic progressions.