The F♯ Dominant 7th chord is a four-note chord made up of F♯, A♯, C♯, and E. It is built from a root, major third, perfect fifth, and minor seventh.
Construction
| Note | Interval | Degree |
|---|---|---|
| F♯ | Root | 1 |
| A♯ | Major 3rd | 3 |
| C♯ | Perfect 5th | 5 |
| E | Minor 7th | ♭7 |
F♯ Dominant 7th Inversions
| Position | Notes |
|---|---|
| Root Position | F♯ – A♯ – C♯ – E |
| 1st Inversion | A♯ – C♯ – E – F♯ |
| 2nd Inversion | C♯ – E – F♯ – A♯ |
| 3rd Inversion | E – F♯ – A♯ – C♯ |
Key Signature
A dominant chord points home to the key a fifth below its root: the F♯ Dominant 7th is the V (dominant) of B Major, so the relevant key signature is that key’s — 5 sharps (F♯, C♯, G♯, D♯, A♯). Spelled as a scale, these notes are F# Mixolydian.
Order of sharps
Sharps are added to a key signature in a fixed order. Each new sharp key adds the next sharp on the list.
Mnemonic: Father Charles Goes Down And Ends Battle
Chords in the Key of B Major
These are the triads built on each degree of the B major scale:
How F♯ Dominant 7th functions in a key
The same chord takes on a different harmonic role depending on the key it appears in. Here is where F♯ Dominant 7th sits diatonically across the common keys:
- In B major, F♯ Dominant 7th is the V chord — the dominant.
- In G♯ minor, F♯ Dominant 7th is the ♭VII chord — a mediant / color chord.