akousia
Start here

C#7 Chord

C#7 adds B to the C sharp major triad. That flat seventh makes it useful before a chord whose root lies a fifth below C sharp.

  • Notes: C sharp-E sharp-G sharp-B
  • Symbol: C#7
  • V7 in F# major
  • Flat seventh
Switch chordC#7

How to play a C#7 chord

Notes: C# - E# - G# - B · symbol C#7

  • Root position

    C# - E# - G# - B
    C4C5
    Right hand 1-2-3-5 · Left 5-3-2-1

  • 1st inversion

    E# - G# - B - C#
    C4C5
    Right hand 1-2-3-5 · Left 5-4-2-1

  • 2nd inversion

    G# - B - C# - E#
    C4C5
    Right hand 1-2-4-5 · Left 5-3-2-1

  • 3rd inversion

    B - C# - E# - G#
    C4C5
    Right hand 1-2-4-5 · Left 5-3-2-1

Where does C#7 belong?

In F# major, C#7 acts as V7 and points toward the tonic.
Play the role cards to hear how its surrounding chords change the job it does; Diatonic Chords explains the basic numbered roles.

  • In F# majorDominant
    V7

    It resolves to F#: E sharp rises to F sharp and B falls a half step.

    F#IBIVC#7V7F#I
  • In F# minorMinor-key dominant
    V7

    The same pull in F# minor, where harmonic minor supplies the raised E sharp.

    F#miBmivC#7V7F#mi
  • In C# bluesBlues home
    I7

    In a 12-bar blues the home chord is itself a 7 chord, and it does not need to resolve.

    C#7I7F#7IV7C#7I7G#7V7
  • In B majorSecondary dominant
    II7

    In B major it borrows a pull toward F#, the V of that key.

    BIC#7II7F#VBI

Progressions to try

  • F#BC#7F#

    C#7 is V7 in F# major; hear its seventh and third lean into the last chord.

  • F#mBmC#7F#m

    The same dominant shape leads into a minor tonic in F# minor.

  • C#7F#7C#7G#7

    In C# blues, the tonic itself carries a seventh; the loop returns to C#7 without losing that blues color.

  • BC#7F#B

    C#7 briefly acts as a secondary dominant, pointing toward the chord after it rather than the main tonic.

Which shape should you use?

On guitar, start with the open x43404 grip. Let the open strings ring and keep any strings marked x silent. The x46464 shape gives you another position when the neighboring chords sit elsewhere on the neck.

On ukulele, start with 1112, played at the 1st fret. The 4544 grip moves the chord to another register.

On piano, play C sharp-E sharp-G sharp-B. Move C sharp up an octave to reach the first inversion, E sharp-G sharp-B-C sharp; the notes remain the same while the lowest voice changes.

What are the inversions?

C sharp is the root, E sharp the major third, G sharp the fifth and B the flat seventh, ten semitones above the root.

  • Root position: C sharp-E sharp-G sharp-B, with C sharp lowest.
  • First inversion: E sharp-G sharp-B-C sharp, written C#7/E# if E sharp is lowest in the whole arrangement.
  • Second inversion: G sharp-B-C sharp-E sharp, written C#7/G# if G sharp is lowest in the whole arrangement.
  • Third inversion: B-C sharp-E sharp-G sharp, written C#7/B if B is lowest in the whole arrangement.

A slash chord names the note in the bass, not merely the lowest note under one hand. Chord Inversions shows how to read that distinction.

How does C#7 differ from C#maj7?

Keep C sharp, E sharp and G sharp; raise the seventh from B to B sharp. The result is C#maj7, whose major seventh changes the pull. Try that one-note change on piano, then use the comparer to hear it in the full chord. See C#maj7 for the other chord's full spelling and roles.

  • C#7

    C# - E# - G# - B
    C4C5

    C# dominant 7

  • C#maj7

    C# - E# - G# - B#
    C4C5

    C# major 7

Try another chord