C♯dim(maj7): C♯/D♭ Diminished Major 7th Piano Chord

Construction

C♯ Diminished Major 7th = Root + Minor 3rd + Diminished 5th + Major 7th = C♯, E, G, B♯

Note	Interval	Degree
C♯	Root	1
E	Minor 3rd	♭3
G	Diminished 5th	♭5
B♯	Major 7th	7

Fingering

Note	Key color	Right hand	Left hand
C♯	black	index finger (2)	little finger (5)
E	white	middle finger (3)	ring finger (4)
G	white	ring finger (4)	middle finger (3)
B♯	white	little finger (5)	index finger (2)

Right hand: index finger (2) on C♯, middle finger (3) on E, ring finger (4) on G, little finger (5) on B♯.

Left hand: little finger (5) on C♯, ring finger (4) on E, middle finger (3) on G, index finger (2) on B♯.

Key Signature

A Diminished Major 7th chord is built from symmetrical or ambiguous intervals, so it doesn't belong to a single key and has no key signature of its own.

Chords in the Key of C♯ Major

These are the triads built on each degree of C♯ Major:

I — C♯ Major (major)

Degree	Numeral	Chord	Quality
1	I	C♯ Major	Major
2	ii	D♯ Minor	Minor
3	iii	E♯ Minor	Minor
4	IV	F♯ Major	Major
5	V	G♯ Major	Major
6	vi	A♯ Minor	Minor
7	vii°	B♯ Diminished	Diminished

C♯ Diminished Major 7th : Frequently Asked Questions

What is the C♯ Diminished Major 7th chord on piano?

The C♯ Diminished Major 7th chord contains the notes C♯ – E – G – B♯. On piano, play these notes together to sound the chord.

What is the C# piano chord?

The C# piano chord (written C♯ Diminished Major 7th) uses the same keys: C♯ – E – G – B♯. The # and ♯ symbols name the same black key.