# F♯ Suspended 4th piano chord (F♯sus4)

F♯sus4 contains F♯, B and C♯. The third replaced by the fourth. F♯ and C♯ are black keys; B is white.

- Canonical page: https://piano.org/chords/suspended-4th/f-sharp/
- Entity: chord:sus4:f-sharp
- Notes: F♯ B C♯
- Formula: 1 4 5
- Intervals from root: P1, P4, P5
- Interval stack (semitones): 5 2
- Also written: F♯sus4, F#sus4, F♯ suspended 4th
- Parameters: A440, 12-TET, 165 mm octave, spans centre to centre

## Construction

| Degree | Note | Interval from root | Semitones |
| --- | --- | --- | --- |
| 1 | F♯ | Perfect unison | 0 |
| 4 | B | Perfect fourth | 5 |
| 5 | C♯ | Perfect fifth | 7 |

## Fingering

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

## Inversions

| Position | Bass | Notes in order | Figured bass | Span |
| --- | --- | --- | --- | --- |
| Root position | F♯ | F♯3 B3 C♯4 | 5/3 | 7 st, 96 mm |
| First inversion (F♯sus4/B) | B | B3 C♯4 F♯4 | 6/3 | 7 st, 96 mm |
| Second inversion (F♯sus4/C♯) | C♯ | C♯4 F♯4 B4 | 6/4 | 10 st, 138 mm |

## Voicings (5)

| Voicing | Notes | Span | Relation | Omits or adds |
| --- | --- | --- | --- | --- |
| Close, root position | F♯3 B3 C♯4 | 7 st, 96 mm | identical | none |
| Close, first inversion | B3 C♯4 F♯4 | 7 st, 96 mm | identical | none |
| Close, second inversion | C♯4 F♯4 B4 | 10 st, 138 mm | identical | none |
| Open, fifth on top | F♯2 C♯3 B3 | 17 st, 234 mm | identical | none |
| Root and third only | F♯3 B3 | 5 st, 69 mm | subset | omits C♯ |

## One-edit neighbors

| Becomes | Edit | Changes | Common tones |
| --- | --- | --- | --- |
| F♯7sus4 | 1 4 5 ♭7 | adds E | 3 |
| F♯ | 1 3 5 | B becomes A♯ | 2 |
| F♯m | 1 ♭3 5 | B becomes A | 2 |
| F♯sus2 | 1 2 5 | B becomes G♯ | 2 |
| F♯maj7 | 1 3 5 7 | B becomes A♯, E♯ | 2 |
| F♯7 | 1 3 5 ♭7 | B becomes A♯, E | 2 |
| F♯m7 | 1 ♭3 5 ♭7 | B becomes A, E | 2 |
| F♯mMaj7 | 1 ♭3 5 7 | B becomes A, E♯ | 2 |
| F♯6 | 1 3 5 6 | B becomes A♯, D♯ | 2 |
| F♯m6 | 1 ♭3 5 6 | B becomes A, D♯ | 2 |
| F♯add9 | 1 3 5 9 | B becomes A♯, G♯ | 2 |
| F♯dim | 1 ♭3 ♭5 | B, C♯ becomes A, C | 1 |

## Set theory

- Absolute pitch classes: {6, 11, 1}
- Relative pitch classes: [0, 5, 7]
- Normal order: [11, 1, 6]
- Prime form: (027)
- Forte number: 3-9
- Interval vector: <010020>

## Frequencies (close root position)

| Note | MIDI | Frequency |
| --- | --- | --- |
| F♯3 | 54 | 185.00 Hz |
| B3 | 59 | 246.94 Hz |
| C♯4 | 61 | 277.18 Hz |

## Questions and answers

### What notes are in F♯sus4?

F♯sus4 contains F♯, B and C♯. The formula is 1, 4, 5.

### How do you play F♯sus4 on piano?

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

### What are the inversions of F♯sus4?

3 positions: root position F♯ B C♯, F♯sus4/B, F♯sus4/C♯.

### What is the difference between F♯sus4 and F♯7sus4?

Adds E. 3 of the notes are shared.

### What is an easy F♯sus4 for small hands?

The root and third only voicing, F♯3 B3, spans 5 semitones or about 69 mm.

### What are the frequencies of F♯sus4?

From F♯3 at A440 in 12-TET: 185.00, 246.94, 277.18 Hz.

### What is the set class of F♯sus4?

Prime form (027), Forte 3-9, interval vector &lt;010020&gt;.

### How do I transpose F♯sus4 to another key?

Keep the 1, 4, 5 formula on the new root. Csus4 is C, F, G; C♯sus4 is C♯, F♯, G♯.

### Is G♭sus4 the same as F♯sus4?

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

## 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:sus4:f-sharp
Last reviewed: 2026-08-12