A flat Major ninth flat fifth

The major ninth ♭5 chord extends major harmony with a ninth while lowering the fifth. Compared with a standard maj9, it sounds more restless and modern: the ninth widens the chord, but the ♭5 introduces a tritone-flavored interior that prevents a fully “sweet” major extension sound. It is useful in jazz, fusion, and neo-soul when you want richness with an edge.

Construction

Practical stack: 1-3-♭5-7-9. In Cmaj9♭5, a working set is C-E-G♭-B-D. Voice leading benefits from spacing: keep 3 and 7 clear and avoid cramming ♭5 and 9 into the same narrow octave.

Usage

Use as a color chord on tonic-related harmony, as a passing chord between clearer maj9 voicings, or in reharmonizations where the composer wants chromatic motion in the middle voices.

Examples

• Modern jazz voicings with altered interior on major chords
• Fusion progressions with shifting fifth colors
• Neo-soul keys parts that avoid overly plain extensions

Play

Anchor 3-7, place 9 above the seventh, and treat ♭5 as a color tone that resolves melodically when possible.

Ear-training cues

Hear ninth width with an altered fifth inside a major-seventh frame.