The F#m/C# chord is an F# minor chord, with the C# (the 5th) as the bass note.
The F# minor chord itself has a dark, melancholy sound. Playing the 5th of the chord (in the case of F#m, the 5th is C#) as the bass note, can make the chord sound even more dark and dramatic, even if it is only a subtle difference.
The chord is also referred to as F sharp minor over C sharp, or F#m ‘slash’ C#, or simply, F sharp minor with an C sharp in the bass.
Technically, the F sharp minor chord with the C sharp in the bass is a second inversion F sharp minor chord.
Some F#m/C# Chord Theory and Info
- The F#m/C# chord contains the notes C#, F# and A.
- It is an F# minor chord with a C# in the bass.
- The root note of F#m/C# is F#, the bass note is C#.