Scale degrees · F♯ major
The ♭5 of F♯ is C
The ♭5 (flat five, written b5) of F♯ (F sharp, F#) is C: a diminished fifth above the root.
F♯ — the root, 1C — the ♭5
How to find it
Count letters first, the root included: F, G, A, B, C. A 5th lands on C.
Then the sound: a diminished fifth is 6 semitones above F♯, which is exactly where C is — no sharp or flat needed.
Where you meet it
The ♭5 halves the octave: a tritone above F♯. It is the 5th of the half-diminished and the diminished chord.
In F♯m7♭5:
F♯ · A · C · E
The ♭5 in every key
| Key | The ♭5 |
|---|---|
| C | G♭ |
| G | D♭ |
| D | A♭ |
| A | E♭ |
| E | B♭ |
| B | F |
| F♯ | C |
| D♭ | A𝄫 |
| A♭ | E𝄫 |
| E♭ | B𝄫 |
| B♭ | F♭ |
| F | C♭ |
Every degree of F♯
Free on iPhone and Android
Name it before
you can count it.
Improvy trains every degree in all 12 keys — the 3, the ♭7, the ♯11 — until you see the note without working it out. A few minutes a day. Free to start; Pro is one payment, never a subscription.
Or try the 60-second test in your browser