(Disclaimer: This is a revision of one of my old articles already posted on the Steem blockchain with the intention of building my Engrave blog)
Today I am finally resurrecting my ''Improv Toolbox'' series as I finally got my main computer back and running. I've been working on a series of tutorials for this year and I hope they prove to be useful for all the improvisation enthusiasts out there.
So Today I'd like to talk about :
Diminished chords are a big subject in itself as it can have various interpretations depending on the musical situation in which they are applied. They symmetrical nature eludes which one of the notes that form it can be considered it's root , that is given by the musical context.
So ... how is a dimished chord formed?
A diminished chord is formed by stacking minor thirds on top of each other , basically there are two basic types of dimished chords , the regular diminished (dim) or the diminished 7th (dim7), their formulas are as follows:
Cdim : 1 , b3 , b5 = C , Eb, Gb
Cdim7 : 1 , b3 , b5 , bb7 = C, Eb , Gb , Bbb ( yes... the correct note is B double flat )
In order to make it more friendly to the nature of the guitar we could think of the dimished chord with this formula:
Cdim7 : 1 , b3 , b5 , 6 = C , Eb, Gb, A
BUT Keep in mind that the chord has a dimished 7th and not a major 6th or this will bring confusion later on , we are just simplifying for mental quickness when improvising.
As with any chord, there is always a particular scale that ''fits like a glove'' and the scale that ''is the most correct'' to play and books teach us is the symmetrical dimished scale.
What is the symmetrical dimished scale?
Well , as the name implies it , it's a symmetrical shape in which we just alternate between a half-step and a whole-step .. like this:
Bear in mind that this particular scale has 8 notes, one more note than the rest of the scales we usually study, translated to a formula we have:
C symmetrical diminished: 1 , 2 , b3 , 4 , b5 , b6 , 6 , 7.
Here is the scale over a Cdim vamp:
I particularly dislike scales in general and this one in particular I can't seem to get friendly with. 7 (or 8 in this case) note scales to me elude tonality and don't have a strong sense of melody. If we just play a scale ''up and down'' we are only introducing intervals of 2nds to the listener ( major or minor , that means whole steps and half steps ) and we are missing the whole intervallic palet of sounds... so I tend to break away from them as much as possible. I focus more in harmony and melodic approaches.
That being said i'd like to give you a cool ''tool'' to play over diminished chords , there are many but this particular one I find very effective. We are going to use one of our pentatonic family formulas that I introduced in one of my first lessons.. which one? The Dominant 7b9 formula!
Here is the diagram for the Dom7b9 pentatonic formula, remember these shapes are transposable:
Why would this work? Well , dimished chords are closely related to Altered dominant chords.. I could make a whole post about this one but let's just make one example so you get the idea.
If we grab the Cdim7 chord we get the notes:
C, Eb , Gb , A ( actually Bbb ... remember ).
Let's alter one note and see what happens:
C , Eb , Gb , Ab. ( now let's do some rearrangement)
Ab , C , Eb, Gb .... what is this? Yes.... it's a Dominant Ab7 chord!
Ab is still part of the diminished scale formula and adding the b9 of the Ab7 chord would bring it even closer to the diminished sound since it is the Bbb note that works as the dimished 7th in the chord, so it's all very closely related. To sum it up.
Cdim = Ab7b9
so playing the Ab Dominant 7b9 pentatonic formula ( 1 , b9 , 3 , 5 , b7 ) would fit like a glove on the C dim chord.
There are much more interpretations of the dimished chord , don't forget... this is just one of them.. and an effective one when improvising in my opinion.
So how does it sound?
Let me apply it to an excercise , this is a dimished chord drill in which we visit all 12 keys just with dimished chords , but i'll only be playing Dom7b9 pentatonic formulas over them, so, this is the road map for the excercise:
Cdim = Ab7b9
Fdim = Db7b9
Bbdim = Gb7b9
Ebdim = B7b9
Abdim = E7b9
Dbdim = A7b9
Gbdim = D7b9
Bdim = G7b9
Edim = C7b9
Adim = F7b9
Ddim = Bb7b9
Gdim = Eb7b9
Let's hear these in action:
Remember this is just an excercise, not intended to be taken with actual ''musical value'' , diminished chords are quite common in popular music so you will be able to find more musical examples in where to apply them.
Here's the backing track so you do your own practice session: