semicord

F#dim F# diminished chord

Notes
F# A C
Formula
1 b3 b5
Semitones
0 3 6 above the root
Also written
Gbdim (Gb Bbb Dbb)
Other symbols
F#°, F#m(b5)

F# to A is a minor third (3 semitones), A to C is a minor third (3 semitones). Two minor thirds stacked, so F# to C is a tritone (6 semitones) instead of a perfect fifth. The four-note F#dim7 and F#m7b5 grow from it by adding a note on top.

F#dim on the piano

C4D4E4F4G4A4B4C5D5E5F5G5A5B5C#4Eb4F#4Ab4Bb4C#5Eb5F#5Ab5Bb5C4F#ACC5

Root position from F#4: F#4, A4, C5. Middle C is C4.

F#dim on the guitar

Standard tuning (E A D G B E). Strings run low E on the left to high e on the right, frets downwards; × is a muted string, ○ an open string, and each dot shows the note it sounds, with the root in blue-green. Every shape below has F# as its lowest note.

F#F#CCF#F#AA××
E-shape barre, root on the E string at fret 2
2 3 4 2 x x (low E to high e)
Sounds F#2 C3 F#3 A3
9fr×F#F#CCF#F#AA×
A-shape barre, root on the A string at fret 9
x 9 10 11 10 x (low E to high e)
Sounds F#3 C4 F#4 A4

The barre shapes are movable: an E-shape chord's root is the note under your first finger on the low E string, an A-shape chord's root is the note on the A string. Slide the same grip up or down to play diminished chords on other roots.

Inversions of F#dim

An inversion puts a note other than the root in the bass. The name is what semicord's chord finder calls those notes played bottom to top; a slash name like C/E means a C chord with E in the bass.

PositionNotes, bass firstNamedListen
Root positionF# A CF#dim
1st inversionA C F#F#dim/A
2nd inversionC F# AF#dim/C

Where F#dim fits

F#dim is vii° in G major, ii° in E minor, vii° in G minor. Its root F# is the leading tone of G: a half step below the tonic, so the chord usually moves up to it.