Diminished Chords are not used often. They consist of these degrees: I, ♭III, ♭V. Diminished 7th chords add a VI degree to the Diminished Chord. Diminished 7th are so easy to remember because all you have to do is use one of the diminished chord patterns (shown below) and find the root note in any position of it. In other words, if you want a C diminished 7 chord, all you have to do is find a C in any place in the pattern. Let me show you.