Dim chords

“Dim” stands for diminished and what happens in these chords is that all tones besides the root are flattened. There are both the diminished triads, the diminished seventh and the half-diminished seventh. In the triad, the third and fifth tones are flattened one semi-step. In the diminished seventh (dim7), a minor third is added to the dim triad. Dim chords are quite uncommon and are mainly used for a transition between two chords that don't have an obvious connection.

See diagrams of dim chords:

C dim D dim E dim F dim G dim A dim B dim

C dim7 D dim7 E dim7 F dim7 G dim7 A dim7 B dim7

C half-dim7 D half-dim7 E half-dim7 F half-dim7 G half-dim7 A half-dim7 B half-dim7


Besides the already mentioned categories, you should know also know of the half-diminished seventh chord. This chord is identical to the diminished seventh except for the seventh note that is flat instead for double flat (it could also be seen as a minor seventh with a lowered fifth). The half-diminished is more commonly written as m7b5.

Comparing the Major Chord with different diminished chords:

C: C – E – G
Cdim: C – Eb – Gb
Cdim7: C – Eb – Gb – A (Bbb)
C half-diminished 7: C – Eb – Gb – Bb

The B double flat (Bbb) in Cdim7 is used since the last tone is theoretically a major sixth.

Formula and steps

The formula for the dim triad chord is 1 - b3 - b5. There are three half steps to the 2nd note and three half steps to the 3rd.

Alternative chord symbols

Besides the dim chord symbol that is presented above, you may also find the alternative degree symbol (°), as in , being used occasionally. Half-diminished seventh chord could also be written with a symbol (ø), as in Cø.

Make use of

And the most important part: how and when to use diminished chords? One of the most common ways is to use them as passing chords. Passing chord can be seen as “in-between chords”, in other words: chords to land on for a short while to create some tension between chords with stronger relationship with the key.

Chord sequences that shows how dim chords can be utilized:

1. C Ebdim G7
2. G Bbdim D7
(The intervals are the same: I biii° V7.)

Examples including dim7:

1. Cmaj7 Dbdim7 Dm7
2. Emaj7 Fdim7 F#m7
(The intervals are the same: Imaj7 bii°7 ii7.)

Examples including half-diminished:

1. Am7 Bm7b5 E7
2. Em7 F#m7b5 B7
(The intervals are the same: i7 iiø7 V7.)