Secondary Dominate/Diminished chords
by Taylor (Jan 02, 2009)
Ok, now, lets first of all review what a dominate chord is before I jump into this incase you don't know what a diminished or dominate chord is.
A dominate chord is found at the 5th degree of every scale. The dominate chord is played mostly so it can resolve or "be pulled" to the tonic (the 1st degree if your scale), but it doesn't always need to resolve to the tonic if you don't want it too. So let's say your in A major, the dominate chord would be E major, if we were in E major it'd be B major, or, put simply, in C it would be G major. Now all of these chords are different then any other major chord because instead of a major 7th, they all share minor sevenths. So when you add that minor seventh, we can now call it a G dominate seventh chord (G7).
I'd also like to add that this doesn't just occur in major scales, you can also find them in minor scales and such. In the key of Dm your dominate chord is gonna be a Am. Have you tried playing it? Doesn't create that much of a "pull" as the dominate chord in the major scale right? Of course your right, it doesn't, not unless you switch the minor chord into a major chord. So try it out.... Does it "pull" more now that you've changed it too major? Hopefully it did cause it not you might be tone deaf.. just kidding.
Now if you want to add more tension, just go ahead and turn it into a A7, which will increase the pull dramatically. If your still not satisfied with that well then hey, just go ahead and add a flat 9.
Diminished chords are pretty much the same thing. You can find the diminished chord on every 7th degree of a major scale, or every 2nd degree in a minor scale. This chord adds A LOT of tension, but it can sound very nice once you resolve to that tonic of the scale.
Now, there's two types of diminished chords (at least to my knowledge). There's fully diminished chords (Dim7) and there's half diminished chords (Dim - usually there's a circle with a line crossed threw it). Now, Half diminished chords are really just a minor 7th chord with a flat fifth, but in some cases you might read it has "half diminished". Fully diminished chords, unlike minor7b5 chords, contain all minor thirds (I think there actually refered to as diminished 2nd's but feel free to check for yourself cause i'm not sure).
Keep in mind that if your in, for example, C major, and your playing a G or G7, you can substitute a C with a Am chord. If your in C major and you play a Bdim7, you can resolve to either C or Am, it's all up to you.
Now, for the lesson we've all been waiting for. Secondary Dominate and Diminished chords. Lets use this example in D major.
D - G - A - D
Your typical I IV V I chord progression. Hear it a lot don't you? Well you might not but a lot of other people do. We don't want to bore them do we? So let's spice this up a little bit.
D - D7 - G - Bb7 - A - D
Lets go threw this one step by step. First of all, you might notice the D7, well of course you'll notice it that was an obvious assumption. Do any of you know what the dominate chord is for the key of G major? Well it's written right there for you, D7. So when we're playing a chord progression like this one, instead of just going over to G from D, we add a D7. It could be any sort of case. If your playing in the key of E major and your hit an A major chord and your about to play a B major chord, go ahead and slap a F#7 right in the middle. Check out the "Extra" chapter at the bottom if you wanna know why I put a Bb7 in there.
Secondary Diminished are the same principles. Well take that same chord progression and instead of using a dominate chord, we're just gonna use a secondary diminished chord.
D - F#dim7 - G - Bb7 - A - D
You get the idea right? F#dim7 is the 7th degree in the key of G major. As long as the chord your resolving into is part of the diatonic scale, you won't run into an complications. One way to make this easy for you is if you look at the root of diminished chord, it's always gonna be a semitone down from the chord your going to. If it's an Am chord your going to, well the 2nd degree of the A minor key Bdim7, and that diminished 7th IS a semitone away from Am. Since every Diminished 7th chord can be 4 other diminished chords you can call it a G#dim7 instead of a Bdim7 if you want to.
I'm glad you decided to read this, because a little bit of extra info isn't gonna hurt.
D - D7 - G - Bb7 - A - D
Now, maybe you could guess that the dominate chord for A major would be a E dominate. Well your right. The Bb is simply a substitution, because Bb, is a tritone higher then E, therefore they can substitute each other. Say I'm in the key of G, if I play a G chord and I'm about to play a Em chord, I can go ahead and add a F7 right in the middle. It's as simple as that, because F is a tritone above B, and B major is the dominate chord for the Em key. Another way to look at it is that this substitution will always be a semitone above the chord your resolving too.
Thank you for reading, I hope you enjoyed this lesson and that it was helpful for you. Any questions let me know. Hope to hear you use this in your own music someday!