Diminished triads and chords

Martin Cohen
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English Diminished triads and chords. Now, before telling you what a diminished triad or chord is, let's look one more time at the minor and major triads and chords. And let me especially look at the intervals between the chord tones. For facility reasons, let me explain this with the C minor and major triads and chords. But, what I will tell is of course valid for all the minor and major chords and triads. So first, let me show you what the intervals between the chord tones are in a major triad. A C Major triad is: C, E, G, as you know. Now, the interval between C and E is that of a major third, and the interval between E and G is that of a minor third. The major third is of course 4 half tones and a minor third 3 half tones. In a C minor triad, the intervals are: well, from C to E flat a minor third (which is 3 half tones) and from E flat to G a major third, which is 4 half tones. So, you see that in a major triad, the intervals are: major third and minor third. And in a minor triad, the intervals are: minor third and major third. Now, nothing prevents me from not choosing major third + minor third, or minor third + major third. But, for example: stacking up two major thirds or two minor thirds. So let's see what this gives. Now, stacking up 2 minor thirds gives the following: so from C to E flat is a minor third, and from E flat a minor third up brings us to G flat. Now, this triad, we call it a diminished triad. Now, when we stack up two major thirds, so from C major a third to E,and from E a major third to G sharp. We call this: an augmented triad. Now, augmented triads are not much used in rock, pop, and blues music. They are used in jazz music. Diminished triads are used in almost all styles of music even if not very frequently, but frequently enough to mention it. So, a diminished triad is made of two stacked minor thirds. Now, let me show you the C diminished triad on the keyboard. Since the C is at the bottom, we call this the C diminished triad in root position. Like always, you can of course also make inversions. Here's the C diminished triad in first inversion, and here the C diminished triad in second inversion. So, every time: take the bottom note and move it to the top. Let me show this with another triad then the C diminished triad. For example: G diminished. From G to B flat is a minor third. And from G flat to D flat is another minor third. This is a G diminished triad. OK, I think that you can find out the inversions yourself. So, one more example. The B flat diminished. So, from B flat to D flat is a minor third, and then from D flat to F flat -which is of course enharmonic equivalent to E- is another minor third. Instead of making triads, It's also possible to add more notes to the chord. So, let's stack up another minor third to the diminished. triad. Let's start again with the C diminished triad. When on top of the G flat, you add another minor third, you would normally arrive at the A, but in the case of the C diminished chord, it's rather a B double flat then an A. But of course, it's enharmonic equivalent to the A. So on the piano, you have to play exactly the same key. Wow, a double flat! Now, why do I call it B double flat and not A? This is because a minor third from G flat, is a B double flats not an A, because when G is letter 1, A is letter 2, and B is letter 3. So the third letter from G is a B, not an A. Also in the G flat minor scale, the first 3 notes would be: G flat, A flat, B double flat. OK, so we call those 4 notes -so the 3 stacked minor thirds: the C diminished seventh chord and we have the following notations for the diminished seventh chord: C dim, or a C with a little circle on the top right side of the C, C dim 7, or C with that same little circle and a 7. Note that sometimes C dim and C with a little circle are used for the diminished triad, and C dim 7 and C with a little circle and the 7 for the diminished seventh chord. Okay, let me illustrate this also with G diminished. So, you saw already the G diminished triad, and you only have to add on top another minor third, which is the F flat. So the enharmonic equivalent of the E. And, one more example: the B flat diminished. So on top of the B flat diminished triad that I already showed, you add another minor third, which is the A double flat. OK, the enharmonic equivalent of the F flat is again the E, and the enharmonic equivalent of the A double flat is of course the G.