A♯sus2: A♯/B♭ Suspended 2nd Piano Chord

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

Scale degree, note, and interval measured from the root.
Degree	Note	Interval from root	Semitones
1	A♯	Perfect unison	0
2	B♯	Major second	2
5	E♯	Perfect fifth	7

Construction

A♯ Suspended 2nd = Root + Major 2nd + Perfect 5th = A♯, B♯, E♯

Note	Interval	Degree
A♯	Root	1
B♯	Major 2nd	2
E♯	Perfect 5th	5

Fingering

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

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

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

A♯ Suspended 2nd Inversions

Root position
A♯ – B♯ – E♯
1st inversion (A♯sus2/B♯)
B♯ – E♯ – A♯
2nd inversion (A♯sus2/E♯)
E♯ – A♯ – B♯

Key Signature

A Suspended 2nd 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 A♯ Major

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

I — A♯ Major (major)

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

Scales That Include the A♯ Suspended 2nd

Db Major (vi)
Ab Major (ii)
Eb Major (V)
Bb Major (I)
F Major (IV)
D Minor (VI)
G Minor (III)
C Minor (VII)

Same Notes, Other Names

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

F Suspended 4th→

A♯ Suspended 2nd : Frequently Asked Questions

What notes are in A♯sus2?

A♯sus2 contains A♯, B♯ and E♯. The formula is 1, 2, 5.

How do you play A♯sus2 on piano?

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

What are the inversions of A♯sus2?

3 positions: root position A♯ B♯ E♯, A♯sus2/B♯, A♯sus2/E♯.

What is the difference between A♯sus2 and A♯add9?

Adds C×. 3 of the notes are shared.

What is an easy A♯sus2 for small hands?

The root and third only voicing, A♯3 B♯4, spans 2 semitones or about 28 mm.

What are the frequencies of A♯sus2?

From A♯3 at A440 in 12-TET: 233.08, 261.63, 349.23 Hz.

What is the set class of A♯sus2?

Prime form (027), Forte 3-9, interval vector <010020>.

How do I transpose A♯sus2 to another key?

Keep the 1, 2, 5 formula on the new root. Csus2 is C, D, G; C♯sus2 is C♯, D♯, G♯.

Is B♭sus2 the same as A♯sus2?

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

A♯ Suspended 2nd 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	A♯3 B♯4 E♯4	7	96 mm	none	identical
Close, first inversion	B♯4 E♯4 A♯4	10	138 mm	none	identical
Close, second inversion	E♯4 A♯4 B♯5	7	96 mm	none	identical
Open, fifth on top	A♯2 E♯3 B♯4	14	193 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	A♯3 B♯4	2	28 mm	omits E♯	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	A♯	A♯3, B♯4, E♯4	5/3	7	96 mm
First inversion: A♯sus2/B♯	B♯	B♯4, E♯4, A♯4	6/3	10	138 mm
Second inversion: A♯sus2/E♯	E♯	E♯4, A♯4, B♯5	6/4	7	96 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
A♯add9	adds C×	1 3 5 9	3
A♯	B♯ becomes C×	1 3 5	2
A♯m	B♯ becomes C♯	1 ♭3 5	2
A♯sus4	B♯ becomes D♯	1 4 5	2
A♯maj7	B♯ becomes C×, G×	1 3 5 7	2
A♯7	B♯ becomes C×, G♯	1 3 5 ♭7	2
A♯m7	B♯ becomes C♯, G♯	1 ♭3 5 ♭7	2
A♯mMaj7	B♯ becomes C♯, G×	1 ♭3 5 7	2
A♯7sus4	B♯ becomes D♯, G♯	1 4 5 ♭7	2
A♯6	B♯ becomes C×, F×	1 3 5 6	2
A♯m6	B♯ becomes C♯, F×	1 ♭3 5 6	2
A♯dim	B♯, E♯ becomes C♯, E	1 ♭3 ♭5	1

Frequencies

Note	MIDI	Frequency
A♯3	58	233.08 Hz
B♯4	60	261.63 Hz
E♯4	65	349.23 Hz

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

Set theory: prime form, Forte number, interval vector

Absolute pitch class set: {10, 0, 5}
Normal order: [10, 0, 5]
Prime form: (027)
Forte number: 3-9
Interval vector: <010020>

Pair	Interval	Semitones	Interval class
A♯ to B♯	Major second	2	2
A♯ to E♯	Perfect fifth	7	5
B♯ to E♯	Perfect fourth	5	5

Where these facts come from

Every value on this page is derived from the note formula for a suspended 2nd applied to the root A♯, 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.

A♯ Suspended 2nd

Fingerings

A♯ Suspended 2nd: notes and degrees