C♯add11 — C♯, E♯, G♯, F♯ — is an add11 chord: major triad + 11th (no 7th, no 9th in between) — a brighter, more harmonically open colour.
Intervals
The C# add 11 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#→F#minor 7th10 semitones
On the keyboard
Each note of the C# add 11 chord highlighted on a piano. Pitch class is what matters — any octave works.
On the guitar
One voicing of the C# add 11 chord on a six-string guitar fretboard.
- 1C#
- 3E#
- 5G#
- 11F#
Common mistakes
The defining note is the 11th (F♯). It sits more than an octave above the root, which is why the chord needs a wide voicing — in tight piano voicings the 11th usually appears in the top register while the root and lower triad tones cluster below.
In context
Functions as a bright extended tonic in rock and modern songwriting, especially in lydian-flavoured passages.
Drill it
The C# add 11 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 puzzleRelated
Frequently asked
- What notes are in a C♯add11 chord?
- C♯add11 contains four notes: C♯, E♯, G♯, F♯.
- How is C♯add11 different from C♯maj7?
- C♯add11 adds the 11th (F♯) on top of the underlying 7th chord. The 11th extends the chord into the next octave and adds harmonic colour.
- When is C♯add11 used in music?
- Functions as a bright extended tonic in rock and modern songwriting, especially in lydian-flavoured passages.