What notes are in a C♯7 chord?

C♯7 contains four notes: C♯ (root), E♯ (major third — same pitch as F), G♯ (perfect fifth), and B (minor seventh).

Is C♯7 the same as D♭7?

Yes, enharmonically — same four pitches. C♯7 lives in F♯-major contexts; D♭7 (D♭-F-A♭-C♭) lives in G♭-major / A♭-major contexts.

Why is the third E♯ and not F?

Major scales use each of the seven letters exactly once. The C♯ major scale runs C♯-D♯-E♯-F♯-G♯-A♯-B♯; the third of C♯7 must sit on the E letter, which is E♯.

When would I see C♯7 in real music?

In music notated in F♯ major or F♯ minor where the V7 needs sharp-side spelling. Bach's WTC includes a C♯-major prelude that uses C♯7 inside its cadences.

C# dominant 7 chord — notes, intervals, and practice

C♯ dominant 7 (C♯7) — C♯, E♯, G♯, B — is C♯ major with a minor 7th. The chord is the V7 of F♯ major and the V7 of F♯ minor. The E♯ (enharmonic to F) is the spelling tell that you're inside a sharp-key context; outside F♯-major literature, the same pitches are written D♭7.

Intervals

The C# dominant 7 chord stacks two thirds on the root. Each interval and its size in semitones:

C#→E#major 3rd4 semitones
E#→G#minor 3rd3 semitones
G#→Bminor 3rd3 semitones

On the keyboard

Each note of the C# dominant 7 chord highlighted on a piano. Pitch class is what matters — any octave works.

On the guitar

One voicing of the C# dominant 7 chord on a six-string guitar fretboard.

1C#
3E#
5G#
♭7B

Common mistakes

C♯7's third is E♯, enharmonic to F. In jazz lead-sheet practice the chord is sometimes written with F as the third — strictly incorrect by the seven-letter rule. The same chord is universally written D♭7 in flat-side music; pick the spelling that matches the surrounding key.

In context

C♯7 is the V7 of F♯ major (C♯7 → F♯maj7) and the V7 of F♯ minor (C♯7 → F♯m). In ii–V–I cadences in F♯ major, the progression runs G♯m7 → C♯7 → F♯maj7. As an altered dominant, C♯7 also appears in jazz reharms substituting for G7 (tritone substitute pointing to C).

Drill it

The C# dominant 7 chord is one of 48 in the Chord Trainer. Open the full trainer to practice it alongside related chords with timing and best-time tracking.

Open the Chord Trainer →Or try today's Etudle puzzle

Frequently asked

What notes are in a C♯7 chord?: C♯7 contains four notes: C♯ (root), E♯ (major third — same pitch as F), G♯ (perfect fifth), and B (minor seventh).
Is C♯7 the same as D♭7?: Yes, enharmonically — same four pitches. C♯7 lives in F♯-major contexts; D♭7 (D♭-F-A♭-C♭) lives in G♭-major / A♭-major contexts.
Why is the third E♯ and not F?: Major scales use each of the seven letters exactly once. The C♯ major scale runs C♯-D♯-E♯-F♯-G♯-A♯-B♯; the third of C♯7 must sit on the E letter, which is E♯.
When would I see C♯7 in real music?: In music notated in F♯ major or F♯ minor where the V7 needs sharp-side spelling. Bach's WTC includes a C♯-major prelude that uses C♯7 inside its cadences.