Caug7: 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	white	index finger (2)	middle finger (3)
G♯	black	middle finger (3)	index finger (2)
B♭	black	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 (Caug7/E)
E – G♯ – B♭ – C
2nd inversion (Caug7/G♯)
G♯ – B♭ – C – E
3rd inversion (Caug7/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:

C 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 C Augmented 7th chord?

The C Augmented 7th chord (C+7 or C7#5) contains four notes: C (root), E (major third), G# (augmented fifth), and Bb (minor seventh). It combines an augmented triad with a minor seventh, creating a bright, tense chord with strong upward pull.

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

Both contain C, E, and Bb. The difference is the fifth: C+7 has G# (augmented fifth) while C7 has G (perfect fifth). The raised fifth adds extra tension and an upward pull that the standard dominant 7th does not have.

How does C Augmented 7th differ from C Augmented?

C Augmented is a three-note triad (C, E, G#). C Augmented 7th adds Bb (minor seventh). The minor seventh adds bluesy tension on top of the augmented triad's floating quality, making it a more harmonically complex chord.

How is C Augmented 7th used in music?

C+7 is used as an altered dominant chord, typically resolving to F Major (the same target as C7). The augmented fifth creates even stronger voice leading: G# pulls up to A while Bb pulls down to A, converging on the third of F Major. It is common in jazz, gospel, and blues.

What songs use Augmented 7th chords?

Augmented 7th chords appear in jazz standards like All the Things You Are and in gospel music where altered dominant chords add emotional intensity. Blues guitarists and jazz pianists use +7 chords as colourful dominant substitutes.

What is the difference between augmented 7th and 7#5?

They are the same chord. C+7, C7#5, and Caug7 all refer to C Augmented 7th (C–E–G#–Bb). The different symbols appear in different notation traditions: +7 in jazz lead sheets, 7#5 in classical analysis, aug7 in educational contexts.

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	C3 E3 G♯3 B♭3	10	138 mm	none	identical
Close, first inversion	E3 G♯3 B♭3 C4	8	110 mm	none	identical
Close, second inversion	G♯3 B♭3 C4 E4	8	110 mm	none	identical
Close, third inversion	B♭3 C4 E4 G♯4	10	138 mm	none	identical
Drop 2	G♯2 C3 E3 B♭3	14	193 mm	none	identical
Drop 3	E2 C3 G♯3 B♭3	18	248 mm	none	identical
Drop 2 and 4	C2 G♯2 E3 B♭3	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	C2 B♭2 E3	16	220 mm	omits G♯	subset
Guide tones, 3 and ♭7	E3 B♭3	6	83 mm	omits C and G♯	subset
Rootless close	E3 G♯3 B♭3	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	C3, E3, G♯3, B♭3	7	10	138 mm
First inversion: Caug7/E	E	E3, G♯3, B♭3, C4	6/5	8	110 mm
Second inversion: Caug7/G♯	G♯	G♯3, B♭3, C4, E4	4/3	8	110 mm
Third inversion: Caug7/B♭	B♭	B♭3, C4, E4, G♯4	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
Caug	drops B♭	1 3 ♯5	3
C7	G♯ becomes G	1 3 5 ♭7	3
C9	G♯ becomes G, D	1 3 5 ♭7 9	3
C	G♯, B♭ becomes G	1 3 5	2
Cmaj7	G♯, B♭ becomes G, B	1 3 5 7	2
Cm7	E, G♯ becomes E♭, G	1 ♭3 5 ♭7	2
Cm7♭5	E, G♯ becomes E♭, G♭	1 ♭3 ♭5 ♭7	2
C7sus4	E, G♯ becomes F, G	1 4 5 ♭7	2
C6	G♯, B♭ becomes G, A	1 3 5 6	2
Cadd9	G♯, B♭ becomes G, D	1 3 5 9	2

Frequencies

Note	MIDI	Frequency
C3	48	130.81 Hz
E3	52	164.81 Hz
G♯3	56	207.65 Hz
B♭3	58	233.08 Hz

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

Set theory: prime form, Forte number, interval vector

Absolute pitch class set: {0, 4, 8, 10}
Normal order: [8, 10, 0, 4]
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