C#7

Q: What notes are in the C#7 chord?

The C#7 chord (C# Dominant 7) contains: C#, E#, G#, B. Its interval structure is shown above in the Theory section.

Q: How do I build C#7 on the keyboard?

Take the root and add the remaining chord tones following the interval formula. The highlight shows chord content, while the inversion control changes which chord tone is in the bass.

Q: Which keys is C#7 found in?

The chord acts as a diatonic degree in several keys — they are marked on the circle of fifths in the "Harmonic context" block.

Q: What can I substitute for C#7?

A substitution depends on harmonic function and voice leading, not only on shared tones. Computed options appear in the "Substitutions" block and should be checked in context.

C# Dominant 7

Octaves

Musical context

ChordC# majorTriad

ChordC#7C# Dominant 7

ArpeggioC# majorBroken triad

ScaleC# major7 notes

KeyC# majorMajor key

ProgressionPop axisSequence

How the chord relates to the scale, mode, key and progression.

Theory

General info

Full name: C# Dominant 7
Symbol: C#7
Root: C#
Quality: Dominant 7

Chord notes

1C#root

3E#major 3rd

5G#perfect 5th

b7Bminor 7th

Functions & resolutions

Typical function in key: viRelative tonic (vi)E major
Stability / tension: High tension — requires resolution
Most common resolutions: F#F# Major D#mD# Minor
Unstable degrees: 3F
4F#
resolves up to the resolution tonic
6A#
b7B
resolves down to the tonic 3rd
Main resolution: C#7source
F#F# Major
Dominant 7th C#7 naturally resolves up a 4th to F#. It is the tritone between the chord's 3rd and 7th that creates this pull.
Other resolutions: C#7source
Deceptive resolution
D#mD# Minor
Instead of the tonic, the dominant resolves to the vi degree. Creates surprise and is often used to extend a musical phrase.
C#7source
Modal resolution
BB Major
In rock and blues, the dominant often moves to bVII or IV instead of the tonic, creating a modal flavor.
C#7source
Jazz reharmonization
G7G Dominant 7
Tritone substitution: C#7 can be replaced by G7 (a tritone away). Both chords share the same tritone between the 3rd and 7th, resolving to the same tonic.
C#7source
Functional resolution
C#sus4C# Sus4
The dominant can resolve beyond the tonic: moving to IV (subdominant) or to a suspension (sus4) are common alternatives in pop and folk music.

Substitutions

Tritone substitution: G7G Dominant 7

Features

Character: Dominant, tense
Characteristic interval: Dominant 7th (b7)
Description: The minor 7th adds dissonance to a major triad. On scale degree V, the chord’s 3rd and 7th form a tritone that directs the voices toward tonic.
Application: V chord in major (resolves to I)
12-bar blues
Rock, Mixolydian