C♭aug7: C♭ Augmented 7th Piano Chord

Root position: either hand, fingers low note to high
Hand	Notes	Fingers
Right	C♭, E♭, G, B♭♭	1-2-3-5
Left	C♭, E♭, G, B♭♭	5-3-2-1

Scale degree, note, and interval measured from the root.
Degree	Note	Interval from root	Semitones
1	C♭	Perfect unison	0
3	E♭	Major third	4
♯5	G	Minor sixth	8
♭7	B♭♭	Minor seventh	10

Construction

C♭ Augmented 7th = Root + Major 3rd + Minor 6th + Minor 7th = C♭, E♭, G, B♭♭

Note	Interval	Degree
C♭	Root	1
E♭	Major 3rd	3
G	Minor 6th	♯5
B♭♭	Minor 7th	♭7

Fingering

Note	Key color	Right hand	Left hand
C♭	white	thumb (1)	little finger (5)
E♭	black	index finger (2)	middle finger (3)
G	white	middle finger (3)	index finger (2)
B♭♭	white	little finger (5)	thumb (1)

Right hand: thumb (1) on C♭, index finger (2) on E♭, middle finger (3) on G, little finger (5) on B♭♭.

Left hand: little finger (5) on C♭, middle finger (3) on E♭, index finger (2) on G, thumb (1) on B♭♭.

C♭ Augmented 7th Inversions

Root position
C♭ – E♭ – G – B♭♭
1st inversion (C♭aug7/E♭)
E♭ – G – B♭♭ – C♭
2nd inversion (C♭aug7/G)
G – B♭♭ – C♭ – E♭
3rd inversion (C♭aug7/B♭♭)
B♭♭ – C♭ – E♭ – G

Key Signature

A Augmented 7th chord is built from symmetrical or ambiguous intervals, so it doesn't belong to a single key and has no key signature of its own.

Chords in the Key of C♭ Major

These are the triads built on each degree of C♭ Major:

I — C♭ Major (major)

Degree	Numeral	Chord	Quality
1	I	C♭ Major	Major
2	ii	D♭ Minor	Minor
3	iii	E♭ Minor	Minor
4	IV	F♭ Major	Major
5	V	G♭ Major	Major
6	vi	A♭ Minor	Minor
7	vii°	B♭ Diminished	Diminished

Same Notes, Other Names

The notes C♭ – E♭ – G – B♭♭ aren’t exclusive to this chord. Depending on which note is the bass and how the chord functions, the same pitches also spell:

B 7♯5→

C♭ Augmented 7th : Frequently Asked Questions

What is the C♭ Augmented 7th chord on piano?

The C♭ Augmented 7th chord contains the notes C♭ – E♭ – G – B♭♭. On piano, play these notes together to sound the chord.

What notes are in the Cb Augmented 7th chord?

The Cb Augmented 7th chord (Cb+7) contains four notes: Cb (root), Eb (major third), G (augmented fifth), and Bbb (minor seventh, enharmonically A). This is the enharmonic equivalent of B+7.

How does Cb Augmented 7th differ from Cb Dominant 7th?

Both contain Cb, Eb, and Bbb. Cb+7 has G (augmented fifth) while Cb7 has Gb (perfect fifth). The raised fifth adds chromatic tension.

How is Cb Augmented 7th used in music?

Cb+7 is the enharmonic equivalent of B+7, resolving to Fb/E Major. In practice, musicians use B+7. The Cb spelling appears in extreme flat-key theoretical contexts.

What genres use Augmented 7th chords?

Augmented 7th chords are common in jazz, gospel, blues, and R&B. Whether spelled Cb+7 or B+7, the sound is identical.

What songs use Augmented 7th chords?

Augmented 7th chords appear in jazz standards and gospel. Cb+7/B+7 resolves to E Major.

What is the difference between +7 and 7#5?

They are the same chord. Cb+7, Cb7#5, and Cbaug7 all refer to Cb Augmented 7th.

C♭ Augmented 7th in detail

Exact

Every pitch class is present and nothing outside the chord is added.

Type	Notes	Semitones	Span	Omissions and additions	Set relation
Close, root position	C♭3 E♭4 G4 B♭♭4	10	138 mm	none	identical
Close, first inversion	E♭4 G4 B♭♭4 C♭4	8	110 mm	none	identical
Close, second inversion	G4 B♭♭4 C♭4 E♭5	8	110 mm	none	identical
Close, third inversion	B♭♭4 C♭4 E♭5 G5	10	138 mm	none	identical
Drop 2	G3 C♭3 E♭4 B♭♭4	14	193 mm	none	identical
Drop 3	E♭3 C♭3 G4 B♭♭4	18	248 mm	none	identical
Drop 2 and 4	C♭2 G3 E♭4 B♭♭4	22	303 mm	none	identical

Reduced

A subset of the pitch classes: the identity is incomplete rather than altered.

Type	Notes	Semitones	Span	Omissions and additions	Set relation
Shell, root ♭7 3	C♭2 B♭♭3 E♭4	16	220 mm	omits G	subset
Guide tones, 3 and ♭7	E♭4 B♭♭4	6	83 mm	omits C♭ and G	subset
Rootless close	E♭4 G4 B♭♭4	6	83 mm	omits C♭	subset

Spans are measured centre to centre at a 165 mm octave (standard keyboard geometry).

Position	Bass note	Notes in order	Figured bass	Semitones	Span
Root position	C♭	C♭3, E♭4, G4, B♭♭4	7	10	138 mm
First inversion: C♭aug7/E♭	E♭	E♭4, G4, B♭♭4, C♭4	6/5	8	110 mm
Second inversion: C♭aug7/G	G	G4, B♭♭4, C♭4, E♭5	4/3	8	110 mm
Third inversion: C♭aug7/B♭♭	B♭♭	B♭♭4, C♭4, E♭5, G5	4/2	10	138 mm

One position per chord tone in the bass. Spans are for close position: voiced inversions appear under Voicings.

Change one note

Chords a single note away, and what moving that note does.

Chord	Change	Formula	Common tones
C♭aug	drops B♭♭	1 3 ♯5	3
C♭7	G becomes G♭	1 3 5 ♭7	3
C♭9	G becomes G♭, D♭	1 3 5 ♭7 9	3
C♭	G, B♭♭ becomes G♭	1 3 5	2
C♭maj7	G, B♭♭ becomes G♭, B♭	1 3 5 7	2
C♭m7	E♭, G becomes E♭♭, G♭	1 ♭3 5 ♭7	2
C♭m7♭5	E♭, G becomes E♭♭, G♭♭	1 ♭3 ♭5 ♭7	2
C♭7sus4	E♭, G becomes F♭, G♭	1 4 5 ♭7	2
C♭6	G, B♭♭ becomes G♭, A♭	1 3 5 6	2
C♭add9	G, B♭♭ becomes G♭, D♭	1 3 5 9	2

Frequencies

Note	MIDI	Frequency
C♭3	59	246.94 Hz
E♭4	63	311.13 Hz
G4	67	392.00 Hz
B♭♭4	69	440.00 Hz

Reference pitch A440, 12-TET, close root position.

Set theory: prime form, Forte number, interval vector

Absolute pitch class set: {11, 3, 7, 9}
Normal order: [7, 9, 11, 3]
Prime form: (0248)
Forte number: 4-24
Interval vector: <020301>

Pair	Interval	Semitones	Interval class
C♭ to E♭	Major third	4	4
C♭ to G	Minor sixth	8	4
C♭ to B♭♭	Minor seventh	10	2
E♭ to G	Major third	4	4
E♭ to B♭♭	Tritone	6	6
G to B♭♭	Major second	2	2

Where these facts come from

Every value on this page is derived from the note formula for a augmented 7th applied to the root C♭, using standard music theory. Nothing here is hand-entered per chord, so the notes, intervals, inversions and frequencies cannot drift out of agreement with each other. Pitches assume 12-TET at A440.

C♭ Augmented 7th

Fingerings

C♭ Augmented 7th: notes and degrees