# A Augmented 7th piano chord (Aaug7)

Aaug7 contains A, C♯, E♯ and G. An augmented triad with the minor seventh added on top. C♯ is a black key; A, E♯ and G are white.

- Canonical page: https://piano.org/chords/augmented-7th/a/
- Entity: chord:augmented-7th:a
- Notes: A C♯ E♯ G
- Formula: 1 3 ♯5 ♭7
- Intervals from root: P1, M3, m6, m7
- Interval stack (semitones): 4 4 2
- Also written: Aaug7, Aaug7, A augmented 7th
- Parameters: A440, 12-TET, 165 mm octave, spans centre to centre

## Construction

| Degree | Note | Interval from root | Semitones |
| --- | --- | --- | --- |
| 1 | A | Perfect unison | 0 |
| 3 | C♯ | Major third | 4 |
| ♯5 | E♯ | Minor sixth | 8 |
| ♭7 | G | Minor seventh | 10 |

## Fingering

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

## Inversions

| Position | Bass | Notes in order | Figured bass | Span |
| --- | --- | --- | --- | --- |
| Root position | A | A3 C♯4 E♯4 G4 | 7 | 10 st, 138 mm |
| First inversion (Aaug7/C♯) | C♯ | C♯4 E♯4 G4 A4 | 6/5 | 8 st, 110 mm |
| Second inversion (Aaug7/E♯) | E♯ | E♯4 G4 A4 C♯5 | 4/3 | 8 st, 110 mm |
| Third inversion (Aaug7/G) | G | G4 A4 C♯5 E♯5 | 4/2 | 10 st, 138 mm |

## Voicings (10)

| Voicing | Notes | Span | Relation | Omits or adds |
| --- | --- | --- | --- | --- |
| Close, root position | A3 C♯4 E♯4 G4 | 10 st, 138 mm | identical | none |
| Close, first inversion | C♯4 E♯4 G4 A4 | 8 st, 110 mm | identical | none |
| Close, second inversion | E♯4 G4 A4 C♯5 | 8 st, 110 mm | identical | none |
| Close, third inversion | G4 A4 C♯5 E♯5 | 10 st, 138 mm | identical | none |
| Drop 2 | E♯3 A3 C♯4 G4 | 14 st, 193 mm | identical | none |
| Drop 3 | C♯3 A3 E♯4 G4 | 18 st, 248 mm | identical | none |
| Drop 2 and 4 | A2 E♯3 C♯4 G4 | 22 st, 303 mm | identical | none |
| Shell, root ♭7 3 | A2 G3 C♯4 | 16 st, 220 mm | subset | omits E♯ |
| Guide tones, 3 and ♭7 | C♯4 G4 | 6 st, 83 mm | subset | omits A and E♯ |
| Rootless close | C♯4 E♯4 G4 | 6 st, 83 mm | subset | omits A |

## One-edit neighbors

| Becomes | Edit | Changes | Common tones |
| --- | --- | --- | --- |
| Aaug | 1 3 ♯5 | drops G | 3 |
| A7 | 1 3 5 ♭7 | E♯ becomes E | 3 |
| A9 | 1 3 5 ♭7 9 | E♯ becomes E, B | 3 |
| A | 1 3 5 | E♯, G becomes E | 2 |
| Amaj7 | 1 3 5 7 | E♯, G becomes E, G♯ | 2 |
| Am7 | 1 ♭3 5 ♭7 | C♯, E♯ becomes C, E | 2 |
| Am7♭5 | 1 ♭3 ♭5 ♭7 | C♯, E♯ becomes C, E♭ | 2 |
| A7sus4 | 1 4 5 ♭7 | C♯, E♯ becomes D, E | 2 |
| A6 | 1 3 5 6 | E♯, G becomes E, F♯ | 2 |
| Aadd9 | 1 3 5 9 | E♯, G becomes E, B | 2 |

## Set theory

- Absolute pitch classes: {9, 1, 5, 7}
- Relative pitch classes: [0, 4, 8, 10]
- Normal order: [5, 7, 9, 1]
- Prime form: (0248)
- Forte number: 4-24
- Interval vector: <020301>

## Frequencies (close root position)

| Note | MIDI | Frequency |
| --- | --- | --- |
| A3 | 57 | 220.00 Hz |
| C♯4 | 61 | 277.18 Hz |
| E♯4 | 65 | 349.23 Hz |
| G4 | 67 | 392.00 Hz |

## Questions and answers

### What notes are in Aaug7?

Aaug7 contains A, C♯, E♯ and G. The formula is 1, 3, ♯5, ♭7.

### How do you play Aaug7 on piano?

Play A, C♯, E♯ and G together. Right hand fingers 1, 2, 3, 5; left hand 5, 3, 2, 1. C♯ is a black key; A, E♯ and G are white.

### What are the inversions of Aaug7?

4 positions: root position A C♯ E♯ G, Aaug7/C♯, Aaug7/E♯, Aaug7/G.

### What is the difference between Aaug7 and Aaug?

Drops G. 3 of the notes are shared.

### What is an easy Aaug7 for small hands?

The guide tones, 3 and ♭7 voicing, C♯4 G4, spans 6 semitones or about 83 mm.

### What are the frequencies of Aaug7?

From A3 at A440 in 12-TET: 220.00, 277.18, 349.23, 392.00 Hz.

### What is the set class of Aaug7?

Prime form (0248), Forte 4-24, interval vector &lt;020301&gt;.

### How do I transpose Aaug7 to another key?

Keep the 1, 3, ♯5, ♭7 formula on the new root. Caug7 is C, E, G♯, B♭; D♭aug7 is D♭, F, A, C♭.

## 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:augmented-7th:a
Last reviewed: 2026-08-12