C diminished seventh (Cdim7) chord on mandolin

Diminished seventh chord (three stacked minor thirds) on C: the notes of the Cdim7 chord are C – E♭ – G♭ – B𝄫.

Dots show:

Basic shapemedium

Position 4medium

Position 7medium

Position 10easy

Tap a string on a diagram to hear just that string. The sound is generated in your browser with a physical string model.

Chord finder Transposer Tuner

What the Cdim7 chord sounds like

A diminished seventh is three stacked minor thirds, so it is symmetrical: four different roots give the same notes. A dramatic, tense passing chord.

Notes of the Cdim7 chord

Degree	Note	Interval from the root
1	C	root
3	E♭	minor third (3 semitones)
5	G♭	diminished fifth (6 semitones)
7	B𝄫	diminished seventh (9 semitones)

How to play it – with fingering

Basic shape

String 1 (E): fret 2, ring finger (G♭5)
String 2 (A): fret 3, little finger (C5)
String 3 (D): fret 1, index finger (E♭4)
String 4 (G): fret 2, middle finger (B𝄫3)

Position 4

String 1 (E): fret 5, ring finger (B𝄫5)
String 2 (A): fret 6, little finger (E♭5)
String 3 (D): fret 4, index finger (G♭4)
String 4 (G): fret 5, middle finger (C4)

Position 7

String 1 (E): fret 8, ring finger (C6)
String 2 (A): fret 9, little finger (G♭5)
String 3 (D): fret 7, index finger (B𝄫4)
String 4 (G): fret 8, middle finger (E♭4)

Tuning: G D A E, like a violin; every note is a pair of strings that you fret together. In the diagram, × means the string is not played, and a circle means an open string.

Similar chords and substitutes

If Cdim7 is too hard, or you want a different colour in the same spot, these chords are worth a try.

Substitutes (by function)

A♭7 – an incomplete dominant: the diminished chord is the top of this seventh chord
C♯ – where it leads (leading tone → root)

Same notes

E♭dim7 – the same notes with a different root
F♯dim7 – the same notes with a different root
Adim7 – the same notes with a different root

Simpler versions

Cdim – all 3 of its notes are in this chord

Frequently asked questions

What notes are in the Cdim7 chord?

C, E♭, G♭, B𝄫. The root is C; the intervals of the other notes from the root: minor third, diminished fifth, diminished seventh.

What is the easiest way to play Cdim7 on mandolin?

The easiest shape above is “Position 10”, rated easy. We show 4 shapes, from open and easy versions to movable barre shapes higher up the neck.

How do I read the chord diagram?

Strings run from the lowest (left) to the highest (right) – tick “Left-handed” to mirror it. Rows are frets; a number at the side shows the starting fret. Dots are fingers (1 index, 2 middle, 3 ring, 4 little), a long bar is a barre, × means don't play that string and ○ means play it open.

How is the Cdim7 chord written?

The chord symbol is Cdim7, and its full name is C diminished seventh.