Lesson 48 · All 12 keys

Major 9th Chord Trainer

Learn how a Major 9th chord is built one semitone-count at a time — a major 7th chord (Lesson 16) with a 9th stacked on top — then put it to work with three MIDI exercises: playing all 12 major 9th chords around the circle of fourths, and 5 jazz plus 5 gospel chord progressions that show off its color, in every key.

How a Major 9th chord is built

A Major 9th chord — written maj9 (e.g. Cmaj9) — is a 5-note chord: a major 7th chord (Lesson 16) with a 9th stacked on top. Every maj9 chord — in any of the 12 keys — is built the exact same way, by counting semitones to the right from a root note:

  1. The starting note — this note names the chord.
  2. Count 4 semitones up from the root — the major 3rd.
  3. Count 3 more semitones up from the 3rd (7 semitones from the root) — the perfect 5th.
  4. Count 4 more semitones up from the 5th (11 semitones from the root) — the major 7th, the same 7th a plain major 7th chord (Lesson 16) uses.
  5. Count 3 more semitones up from the 7th (14 semitones from the root — an octave plus a major 2nd) — the 9th, stacked on top of a complete major 7th chord.
Example — Cmaj9: start on C, count 4 semitones right to reach E, count 3 semitones more to reach G, count 4 semitones more to reach B, count 3 semitones more to reach D. C‑E‑G‑B‑D is the Cmaj9 chord.
A major 9th chord still contains the full major 7th chord underneath (root, 3rd, 5th, 7th) — it just adds a lush 9th on top, one step beyond the plain major 7th chord’s color.

Try it: pick a root and build the chord step by step

Step 1 of 5
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Chord toneNoteSemitones from rootMIDI #

All 12 major 9th chords at a glance

ChordRootMajor 3rdPerfect 5thMajor 7th9th

This MIDI exercise plays all 12 major 9th chords, one after another, moving around the circle of fourths — each chord's root sits a perfect 4th (5 semitones) above the last one: C → F → B♭ → E♭ → A♭ → D♭ → G♭/F♯ → B → E → A → D → G → back to C. Every chord is played as a full 5-note Major 9th chord (root, major 3rd, perfect 5th, major 7th, 9th together).

Chord 1 of 12
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The 12 chords, in circle-of-fourths order

#ChordRootMajor 3rdPerfect 5thMajor 7th9th

Five jazz chord progressions built around the Major 9th chord. Pick a progression and play it in one key or cycle through all 12.

Key of C
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Progression in C

DegreeChordNotes

Five gospel chord progressions built around the Major 9th chord. Pick a progression and play it in one key or cycle through all 12.

Key of C
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Progression in C

DegreeChordNotes