Chords I, IV, & V
So, in doing the Improv section I’ve been trying as much to both intellectually understand the theory and also to internalize as much as possible. My question concerns the I, IV, & V chords. Why are these the chords on which blues based? Why not the II, III, and VII, for instance? Also, why only three chords? Why not four or two?
This might be a bit like the kid who asks his mom why the sky is blue but I thought I’d ask anyway.
If this is how it’s always been done, there’s probably a certain amount of natural selection going on. BTW, are these three chords also standard on other genres, like rock, country, beebop, or swing? Just curious, actually, but I am trying to place all this new knowledge in some context.
There's a lot of math that aligns well for the I, IV, and V to work well (look at the Circle of 5ths for a clue to this), but the order, and length of the progression, is just how it developed in the blues. Those chords are the most common chords in music in general (again, especially the I and V... the ii is very common as well), so the time you put into getting to know the chords is time well-spent. In the end, you'll get to know all of the chords, but a strong ability to play within those three chords will pay off big dividends. I recommend you take a peak at Music Theory Study 6. Though you're not there in your studies yet, it will be informative to watch.
thank you.
thank you.
Maybe you've heard of Harlan Howard's definition of a great country song as "three chords and the truth"? Well, the I, IV and V are the three chords he's talking about.
Yes, I’ve heard that Before. Lol. Always thought it was a great line, too.
Hello Ace. The other chords are used every now and again (especially in 8 Bar blues ballads, and in more jazz-influenced blues), but besides that, our good ‘ole 12 Bar structure is just what’s been handed down to us in the evolution of the style. One simple observation is that the I and V chords are the strongest chords structurally in music. The IV is fairly strong as well. The order of the chords can be mixed around (especially in 8 Bar), but for some reason, the 12 Bar remains pretty intact as the progression I teach you.