Major 6/9
Ab6/9 is a major seventh chord built on Ab. It has a warm, stable, and slightly dreamy quality — the sound of resolution and arrival in jazz harmony. Major seventh chords appear on the I and IV degrees of major keys and are foundational to jazz piano voicing.
15 voicings · major
Left Hand
Right Hand
Left Hand
Right Hand
Left Hand
Right Hand
Left Hand
Right Hand
Left Hand
Right Hand
Left Hand
Right Hand
Melody (Bb5) doubled an octave below (Ab4) with chord tones in between
Left hand alternates between bass note and chord
Beat 1 & 3 — Ab3
Beat 2 & 4 — C, F, Bb
Left hand alternates between bass note and chord
Beat 1 & 3 — Eb3
Beat 2 & 4 — C, F, Bb
The major seventh chord most commonly functions as the I (tonic) or IV (subdominant) chord in a major key (Levine, The Jazz Theory Book). As the I chord, Ab6/9 is the point of harmonic resolution — the destination of ii-V-I progressions. As the IV chord, it adds warmth and colour without the tension of dominant harmony. Jazz pianists voice major sevenths with rootless voicings to create the characteristic "Bill Evans sound" (Levine, The Jazz Piano Book).
Commonly paired with the Ionian mode (major scale) when functioning as I, or the Lydian mode (#4) when functioning as IV — the raised fourth avoids the "avoid note" of the natural fourth (Aebersold, Jazz Handbook). The Lydian sound is brighter and more modern.
Major seventh chords are typically points of resolution rather than departure. In a ii-V-I progression, Ab6/9 is the destination (Mulholland & Hojnacki, The Berklee Book of Jazz Harmony).
ii-V-I
Abm7 is the ii, leading through V7 to resolve on Ab6/9
I-vi-ii-V turnaround
Ab6/9 — vi7 — ii7 — V7, cycling back to I
IV chord
Ab6/9 as the IV in a key a 4th below, adding warmth
Ab6/9 is a four-note chord containing the root (Ab), major third, perfect fifth, and major seventh. It produces a lush, stable sound that defines the tonic in jazz harmony (Levine, The Jazz Theory Book).
The most common voicings are shell (root, 3rd, 7th), rootless Type A (3rd, 5th, 7th, 9th), and rootless Type B (7th, 9th, 3rd, 5th). In a band setting, Levine recommends omitting the root since the bassist plays it (The Jazz Piano Book). These are sometimes called "left-hand voicings."
Ab6/9 is used as a tonic chord (I) or subdominant chord (IV) in jazz standards. It appears in virtually every jazz standard as a point of harmonic resolution.
Rootless voicings for major seventh chords are introduced as "left-hand voicings" with two positions (A and B) that alternate for smooth voice leading.
— Levine, The Jazz Piano Book, pp. 41-50
The Lydian mode is the preferred scale choice for major seventh chords functioning as IV, avoiding the natural fourth as an "avoid note."
— Levine, The Jazz Theory Book, pp. 33-37