F♯aug: F♯/G♭ Augmented Piano Chord

Root position: either hand, fingers low note to high
Hand	Notes	Fingers
Right	F♯, A♯, C×	1-3-5
Left	F♯, A♯, C×	5-3-1

Scale degree, note, and interval measured from the root.
Degree	Note	Interval from root	Semitones
1	F♯	Perfect unison	0
3	A♯	Major third	4
♯5	C×	Minor sixth	8

Construction

F♯ Augmented = Root + Major 3rd + Minor 6th = F♯, A♯, C♯♯

Note	Interval	Degree
F♯	Root	1
A♯	Major 3rd	3
C♯♯	Minor 6th	♯5

Fingering

Note	Key color	Right hand	Left hand
F♯	black	thumb (1)	little finger (5)
A♯	black	middle finger (3)	middle finger (3)
C♯♯	white	little finger (5)	thumb (1)

Right hand: thumb (1) on F♯, middle finger (3) on A♯, little finger (5) on C♯♯.

Left hand: little finger (5) on F♯, middle finger (3) on A♯, thumb (1) on C♯♯.

F♯ Augmented Inversions

Root position
F♯ – A♯ – C♯♯
1st inversion (F♯aug/A♯)
A♯ – C♯♯ – F♯
2nd inversion (F♯aug/C♯♯)
C♯♯ – F♯ – A♯

Key Signature

A Augmented 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 F♯ Major

These are the triads built on each degree of F♯ Major:

I — F♯ Major (major)

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

Same Notes, Other Names

The notes F♯ – A♯ – C♯♯ aren’t exclusive to this chord. Depending on which note is the bass and how the chord functions, the same pitches also spell the following:

A♯ Augmented→D Augmented→

F♯ Augmented : Frequently Asked Questions

What notes are in F♯aug?

F♯aug contains F♯, A♯ and C×. The formula is 1, 3, ♯5.

How do you play F♯aug on piano?

Play F♯, A♯ and C× together. Right hand fingers 1, 3, 5; left hand 5, 3, 1. F♯ and A♯ are black keys; C× is white.

What are the inversions of F♯aug?

3 positions: root position F♯ A♯ C×, F♯aug/A♯, F♯aug/C×.

What is the difference between F♯aug and F♯aug7?

Adds E. 3 of the notes are shared.

What is an easy F♯aug for small hands?

The root and third only voicing, F♯3 A♯3, spans 4 semitones or about 55 mm.

What are the frequencies of F♯aug?

From F♯3 at A440 in 12-TET: 185.00, 233.08, 293.66 Hz.

What is the set class of F♯aug?

Prime form (048), Forte 3-12, interval vector <000300>.

How do I transpose F♯aug to another key?

Keep the 1, 3, ♯5 formula on the new root. Caug is C, E, G♯; D♭aug is D♭, F, A.

Is G♭aug the same as F♯aug?

Enharmonically yes: the same piano keys and the same sound, spelled differently.

F♯ Augmented 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	F♯3 A♯3 C×4	8	110 mm	none	identical
Close, first inversion	A♯3 C×4 F♯4	8	110 mm	none	identical
Close, second inversion	C×4 F♯4 A♯4	8	110 mm	none	identical
Open, fifth on top	F♯2 C×3 A♯3	16	220 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	Fit
Root and third only	F♯3 A♯3	4	55 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	F♯	F♯3, A♯3, C×4	5/3	8	110 mm
First inversion: F♯aug/A♯	A♯	A♯3, C×4, F♯4	6/3	8	110 mm
Second inversion: F♯aug/C×	C×	C×4, F♯4, A♯4	6/4	8	110 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
F♯aug7	adds E	1 3 ♯5 ♭7	3
F♯	C× becomes C♯	1 3 5	2
F♯maj7	C× becomes C♯, E♯	1 3 5 7	2
F♯7	C× becomes C♯, E	1 3 5 ♭7	2
F♯6	C× becomes C♯, D♯	1 3 5 6	2
F♯add9	C× becomes C♯, G♯	1 3 5 9	2
F♯m	A♯, C× becomes A, C♯	1 ♭3 5	1
F♯dim	A♯, C× becomes A, C	1 ♭3 ♭5	1
F♯sus2	A♯, C× becomes G♯, C♯	1 2 5	1
F♯sus4	A♯, C× becomes B, C♯	1 4 5	1

Frequencies

Note	MIDI	Frequency
F♯3	54	185.00 Hz
A♯3	58	233.08 Hz
C×4	62	293.66 Hz

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

Set theory: prime form, Forte number, interval vector

Absolute pitch class set: {6, 10, 2}
Normal order: [2, 6, 10]
Prime form: (048)
Forte number: 3-12
Interval vector: <000300>

Pair	Interval	Semitones	Interval class
F♯ to A♯	Major third	4	4
F♯ to C×	Minor sixth	8	4
A♯ to C×	Major third	4	4

Where these facts come from

Every value on this page is derived from the note formula for a augmented applied to the root F♯, 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.

F♯ Augmented

Fingerings

F♯ Augmented: notes and degrees