# C Major 9th piano chord (Cmaj9)

Cmaj9 contains C, E, G, B and D. A major seventh with the ninth added on top. Every note is a white key.

- Canonical page: https://piano.org/chords/major-9th/c/
- Entity: chord:major-9th:c
- Notes: C E G B D
- Formula: 1 3 5 7 9
- Intervals from root: P1, M3, P5, M7, M9
- Interval stack (semitones): 4 3 4 3
- Also written: Cmaj9, Cmaj9, C major 9th
- Parameters: A440, 12-TET, 165 mm octave, spans centre to centre

## Construction

| Degree | Note | Interval from root | Semitones |
| --- | --- | --- | --- |
| 1 | C | Perfect unison | 0 |
| 3 | E | Major third | 4 |
| 5 | G | Perfect fifth | 7 |
| 7 | B | Major seventh | 11 |
| 9 | D | Major ninth | 14 |

## Fingering

Rest your right hand over the notes with finger 1 on C, finger 2 on E, finger 3 on G, finger 4 on B, finger 5 on D. The left hand mirrors it.
Right hand 1-2-3-4-5, left hand 5-4-3-2-1. Source: piano.org fingering method v1.

## Inversions

| Position | Bass | Notes in order | Figured bass | Span |
| --- | --- | --- | --- | --- |
| Root position | C | C3 E3 G3 B3 D4 | 9 | 14 st, 193 mm |
| First inversion (Cmaj9/E) | E | E3 G3 B3 C4 D4 | 7/6/5 | 10 st, 138 mm |
| Second inversion (Cmaj9/G) | G | G3 B3 C4 D4 E4 | 7/4/3 | 9 st, 124 mm |
| Third inversion (Cmaj9/B) | B | B3 C4 D4 E4 G4 | 7/4/2 | 8 st, 110 mm |
| Fourth inversion (Cmaj9/D) | D | D3 E3 G3 B3 C4 | 9/7/5 | 10 st, 138 mm |

## Voicings (11)

| Voicing | Notes | Span | Relation | Omits or adds |
| --- | --- | --- | --- | --- |
| Close, root position | C3 E3 G3 B3 D4 | 14 st, 193 mm | identical | none |
| Close, first inversion | E3 G3 B3 C4 D4 | 10 st, 138 mm | identical | none |
| Close, second inversion | G3 B3 C4 D4 E4 | 9 st, 124 mm | identical | none |
| Close, third inversion | B3 C4 D4 E4 G4 | 8 st, 110 mm | identical | none |
| Close, fourth inversion | D3 E3 G3 B3 C4 | 10 st, 138 mm | identical | none |
| Drop 2 | B2 C3 E3 G3 D4 | 15 st, 206 mm | identical | none |
| Drop 3 | G2 C3 E3 B3 D4 | 19 st, 261 mm | identical | none |
| Drop 2 and 4 | E2 B2 C3 G3 D4 | 22 st, 303 mm | identical | none |
| Shell, root 9 3 | C2 D3 E3 | 16 st, 220 mm | subset | omits G |
| Guide tones, 3 and 9 | E3 D4 | 10 st, 138 mm | subset | omits C and G |
| Rootless close | E3 G3 B3 D4 | 10 st, 138 mm | subset | omits C |

## One-edit neighbors

| Becomes | Edit | Changes | Common tones |
| --- | --- | --- | --- |
| Cmaj7 | 1 3 5 7 | drops D | 4 |
| Cadd9 | 1 3 5 9 | drops B | 4 |
| C9 | 1 3 5 ♭7 9 | B becomes B♭ | 4 |
| C7 | 1 3 5 ♭7 | B, D becomes B♭ | 3 |
| CmMaj7 | 1 ♭3 5 7 | E, D becomes E♭ | 3 |
| C6 | 1 3 5 6 | B, D becomes A | 3 |
| Cm9 | 1 ♭3 5 ♭7 9 | E, B becomes E♭, B♭ | 3 |

## Set theory

- Absolute pitch classes: {0, 4, 7, 11, 2}
- Relative pitch classes: [0, 4, 7, 11, 2]
- Normal order: [11, 0, 2, 4, 7]
- Prime form: (01358)
- Forte number: not claimed for this cardinality
- Interval vector: <122230>

## Frequencies (close root position)

| Note | MIDI | Frequency |
| --- | --- | --- |
| C3 | 48 | 130.81 Hz |
| E3 | 52 | 164.81 Hz |
| G3 | 55 | 196.00 Hz |
| B3 | 59 | 246.94 Hz |
| D4 | 62 | 293.66 Hz |

## Questions and answers

### What notes are in Cmaj9?

Cmaj9 contains C, E, G, B and D. The formula is 1, 3, 5, 7, 9.

### How do you play Cmaj9 on piano?

Play C, E, G, B and D together. Right hand fingers 1, 2, 3, 4, 5; left hand 5, 4, 3, 2, 1. Every note is a white key.

### What are the inversions of Cmaj9?

5 positions: root position C E G B D, Cmaj9/E, Cmaj9/G, Cmaj9/B, Cmaj9/D.

### What is the difference between Cmaj9 and Cmaj7?

Drops D. 4 of the notes are shared.

### What is an easy Cmaj9 for small hands?

The close, third inversion voicing, B3 C4 D4 E4 G4, spans 8 semitones or about 110 mm.

### What are the frequencies of Cmaj9?

From C3 at A440 in 12-TET: 130.81, 164.81, 196.00, 246.94, 293.66 Hz.

### What is the set class of Cmaj9?

Prime form (01358), interval vector &lt;122230&gt;.

### How do I transpose Cmaj9 to another key?

Keep the 1, 3, 5, 7, 9 formula on the new root. C♯maj9 is C♯, E♯, G♯, B♯, D♯; D♭maj9 is D♭, F, A♭, C, E♭.

## Provenance

Every derived value above is computed by the piano.org theory kernel from the root, the quality and the stated parameters. Nothing is hand-entered per chord.

Machine record: https://piano.org/api/knowledge/v1/entities/chord:major-9th:c
Last reviewed: 2026-08-12