Minor 9th Chords on Piano

The minor 9th chord extends the minor 7th by adding the ninth — creating a smooth, dark, and sophisticated voicing. It is the signature chord of neo-soul, lo-fi, and modern R&B, and serves as a rich ii chord in jazz progressions.

Formula: Root – Minor 3rd – Perfect 5th – Minor 7th – Major 9th

Scale degrees: 1–♭3–5–♭7–9

Sound: Smooth, dark, sophisticated, mellow

Symbol: m9, min9 (Cm9, Dm9)

The neo-soul sound: Dm9 → G9 → Cmaj9 (the ii–V–I with 9ths) is the foundation of modern jazz and neo-soul harmony. The ninth adds warmth to the minor 7th without changing its smooth, dark character. Erykah Badu, D'Angelo, and lo-fi producers all build on minor 9th voicings.

Minor 9th Chord in All 18 Keys