Wednesday, July 13, 2011

Quick Question About The Blues...

Q: Hey Chris, I’ve been working through some of the exercises in your book (specifically harmonizing the Major scale) and wondered about the standard Blues progression. People will often say ‘Play a blues in G Major’  Now this isn’t a diatonic progression – G7 is the V chord from C Maj, C7 is the V chord from E Major and D7 is the V chord from G Major. So why would this be referred to as a Blues in G Major. Is it just that the Blues progression is a kind of special case, that sits outside the normal diatonic rules? A basic question I know, but the harmonizing exercises in your book have got me thinking about this sort of thing. 

A: Generally, at least in my circle of partners in crime, we say "Play a Blues in G" or "Play a minor Blues in G." Or even "Play a Jazz Blues in G."  But not so often a "Blues in G major" it isn't wrong of course but sort of unnecessary. I guess you might say "major" just to make sure the person you are talking to doesn't play a minor Blues, but I think most players wouldn't confuse a Blues with a minor Blues.

When you try to make theoretic sense of a Blues it doesn't usually work out to well. If you had a time machine and went back to Bach's time and explained (in German) in pure theoretical terms about this style called the Blues, he would probably think you a nut case. Of course we know from playing it and listening to it, it works out pretty well though, at least to our modern ears.

It is sort of diatonic and I say that because it is based on the I, IV and V chords of one key. The "sort of" is because we change the I and IV chords to dominant chords. If St. Peter wouldn't let me through the pearly gates unless I could explain why the I chord is dominant in the Blues, I suppose I could tell him that it sort of functions as a V/IV chord. Right? a C7 in the key of C is the V chord of the IV chord. C7 goes nicely to F, a secondary dominant chord.

The dominant IV chord can't really be explained but if I had to come up with some sort of explanation at gunpoint, and I'm not really sure this is right, but I would say that as we like to play a minor pentatonic scale over the progression, the minor 3rd in the scale, is the b7 in the dominant IV chord. Right? the Eb note in the C minor pentatonic scale is the b7th of an F7 chord. Maybe that has something to do with it, but I'm not sure. The dominant V chord doesn't need much explaining.

All in all, the truth is that slaves liked the way that the minor pentatonic scale sounded of the white man's I-IV-V progression. And the major triads eventually turned into dominant chords. Maybe because of the b3rd in the scale but that is just a guess on my part. 

7 comments:

BillCo said...

I've given considerable thought to this (way too much actually) and my way of explaining it boils down to the fact that blues simply isn't western music. It's African. It's full of what we would call micro-tonal intervals from a European perspective. It is based on scales/intervals that simply do not exist in western theory.

I see blues as being a modal form in this context. As you probably know already, if you drop the root of each chord and play just the 3 + b7 your reference tone turns into a static interval that moves just one semitone each way throughout the whole progression. So what you are really doing is playing these "microtonal" scales over a tone centre that only really shifts by a semi tone around the root.

This is why the b7 is so integral to blues. Without it you lose the modality and the microtonics stop working.

BillCo said...
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-CJ said...

There is an interesting story I found about a Blues recording from 1906. Basically you can hear an African use the Blues scale bending the minor 3rd up to a major 3rd at times. If you play an Eb blues behind it you will really hear it as the Blues. I could be argued that this recording is like the missing link to the Blues being African theory. Although some people will just tell you to shut up and play your guitar and quit thinking so much. Anyway, here is the link: http://www.wbgo.org/blog/blues-recording-congo-1906

BillCo said...

Wow, Thanks for sharing that link, man! That guy is playing straight up BB King! It's not quite a 12 bar 1-IV-V and the phrasing is not what we are used to, but sure is the blues alright. Amazing. I'd love to hear those guys singing/chanting/drumming... that would be something!

As for shut up an play etc... I get that, but we're not all blessed with the natural musicality of Wes - people like me have to study it and work it hard, or we wind up w*nking our way through the cliche book like Bonamassa!

BillCo said...

Wow, Thanks for sharing that link, man! That guy is playing straight up BB King! It's not quite a 12 bar 1-IV-V and the phrasing is not what we are used to, but sure is the blues alright. Amazing. I'd love to hear those guys singing/chanting/drumming... that would be something!

As for shut up an play etc... I get that, but we're not all blessed with the natural musicality of Wes - people like me have to study it and work it hard, or we wind up w*nking our way through the cliche book like Bonamassa!

BillCo said...

Wow, Thanks for sharing that link, man! That guy is playing straight up BB King! It's not quite a 12 bar 1-IV-V and the phrasing is not what we are used to, but sure is the blues alright. Amazing. I'd love to hear those guys singing/chanting/drumming... that would be something!

As for shut up an play etc... I get that, but we're not all blessed with the natural musicality of Wes - people like me have to study it and work it hard, or we wind up w*nking our way through the cliche book like Bonamassa!

-CJ said...

Try playing an Eb Blues over the MP3, you'll really hear it. My students always freak out when I do it.