Why does the minor pentatonic fit a major blues

B

Bolar

Guest
I play with some friends once or twice a week, and this question came up, more specifically why we play the minor third over a major type chord. Same question has been seen here from time to time, hence this post......
So how does the minor third fit according to theory? Short answer: It doesn't!

It is often explained, as blues doesn,t fit standard theory, and we are breaking the rules, when playing blues. As for the minor pentatonic, that's not entirely true - the notes in the scale fits standard theory perfectly, only rule broken is when putting a name to those notes.

In blues we play dom7th chords, and the possible extensions to 7th chords are: b9, 9, #9, 11, #11, b13, 13.
In the key of C, that gives us, including chord notes, following notes:
C7: C, Db, D, D#, E, F, F#, G, Ab, A, Bb
F7: F, Gb, G, G#, A, Bb, B C, Db, D, Eb
G7: G, Ab, A, A#, B, C, C#, D, Eb, E, F

When looking at these notes, the following 9 fits all 3 chords: C, Db/C#, D, D#/Eb, F, G, G#/Ab, A, A#/Bb
Notice, that some notes have different names, depending on the chord, but it is still the same note on the fretboard.
You might know the rule, "you can only use a letter once in a scale" , from the major and minor scales.

Applying this rule to the above 9 notes, means getting rid of some of them.
The C, F & G are only choices so we keep those. The D#/Eb is needed for the F7, so Db & D have to go. The A#/Bb is needed for the C7, so Ab & A have to go.
This leaves 5 notes : C, D#/Eb, F, G, A#/Bb.
So over the C7, you can't play the minor 3rd (Eb), but you can play the #9 (D#) and same thing with the G7 - you play A#, not Bb.
For convenience we stick with only one name per note and end up with C, Eb, F, G, Bb, which is the minor pentatonic scale , we all know.
 
JPsuff

JPsuff

Blackstar Artist
What I know about Music Theory could barely fill a small thimble, so I have no factual way to back this up....

But from a common sense point of view it just seems to me that a five-note scale can be applied to many more and varied situations simply because it's just five notes. "Full size" seven-note scales appear to be more restrictive in their use because of those extra two notes which seem to be useful in very specific situations.

Does that make any sense? :confused:
 
MarkDyson

MarkDyson

Blues Hound Wannabe
And here I thought it came about because the number of fingers on one hand was as high as a typical guitarist could count. :whistle:
 
B

Bolar

Guest
JPsuff said:
What I know about Music Theory could barely fill a small thimble, so I have no factual way to back this up....

But from a common sense point of view it just seems to me that a five-note scale can be applied to many more and varied situations simply because it's just five notes. "Full size" seven-note scales appear to be more restrictive in their use because of those extra two notes which seem to be useful in very specific situations.

Does that make any sense? :confused:
Click to expand...

It makes sense. I think the lack of minor 2nd intervals in the common pentatonic scales is a key feature. Minor 2nd intervals are unavoidable in scales with more than 5 notes.
 
R

Randy S

Blues Junior
JPsuff said:
What I know about Music Theory could barely fill a small thimble, so I have no factual way to back this up....

But from a common sense point of view it just seems to me that a five-note scale can be applied to many more and varied situations simply because it's just five notes. "Full size" seven-note scales appear to be more restrictive in their use because of those extra two notes which seem to be useful in very specific situations.

Does that make any sense? :confused:
Click to expand...
I am not sure of this but I think the pentatonic scale came about because the minor pentatonic fits all three minor modes and the major pentatonic fits all three major modes. The notes that are different between the modes are left out of the pentatonic scale. So you can use a pentatonic scale over a chord- minor pentatonic over a minor chord and major pentatonic over a major chord- without knowing the chords function (ie. is a I, a IV, a ii, etc.). Which is the same as saying you don't which mode the chord progression is in.

The Blues, of course, doesn't follow this rule set.
 
BoogieMan

BoogieMan

Blues Junior
Bolar said:
I play with some friends once or twice a week, and this question came up, more specifically why we play the minor third over a major type chord.
Click to expand...

According to Stich, the sound of a major chord structure on the bottom being played with a minor scale system on top (he calls it a "sandwich") is the sound of the blues. It's nice to see why it all works!
 
david moon

david moon

Attempting the Blues
So in a nutshell, these notes work because they are in the extended family of dom7 chords, and they are common to the I7, IV7, and V7 extended families?

Just one example, in key of C, Eb is the #9 in C, the b7 in F and the b13 in G.

Did I get that right?
 
sdbrit68

sdbrit68

Student Of The Blues
Cant remember whether it was Marty or Griff who said it doesnt really work, but its close enough, so we have come to accept the sound as being correct, so now we accept it as the sound of the blues.

I know its on one of my dvd's somewhere, someone ask @Griff
 
B

Bolar

Guest
david moon said:
So in a nutshell, these notes work because they are in the extended family of dom7 chords, and they are common to the I7, IV7, and V7 extended families?

Just one example, in key of C, Eb is the #9 in C, the b7 in F and the b13 in G.

Did I get that right?
Click to expand...
Exactly. And if you take the root & the 7th from each chord and put them together, you come up with the same scale. So when sticking to the minor pentatonic scale, we aren't playing any 3rd's at all.
 
Griff

Griff

Vice Assistant General Manager
Staff member
I've never heard that particular history, so I can't really say much about it. It's an interesting story if it's true.

Playing Minor Pentatonic over blues just works, and it took me a long time to accept it. It breaks a lot of rules, but it works somehow because it's a sound we're accustomed to hearing.
 
sdbrit68

sdbrit68

Student Of The Blues
Griff said:
I've never heard that particular history, so I can't really say much about it. It's an interesting story if it's true.

Playing Minor Pentatonic over blues just works, and it took me a long time to accept it. It breaks a lot of rules, but it works somehow because it's a sound we're accustomed to hearing.
Click to expand...

wow, I was kinda correct.......I shall celebrate with some dunkin doughnuts this morning
 
B

Bolar

Guest
Griff said:
I've never heard that particular history, so I can't really say much about it. It's an interesting story if it's true.

Playing Minor Pentatonic over blues just works, and it took me a long time to accept it. It breaks a lot of rules, but it works somehow because it's a sound we're accustomed to hearing.
Click to expand...

Mind you, I'm well aware , that my analysis doesn't say anything about where the minor pentatonic originates from, and it doesn't explain the nature of blues music either - far from it - that was never my intention. But countless are the times, I have heard that the minor pentatonic doesn't fit theory and playing b3rd over a dom7th chord breaks the rules.
Many people, me included, have wondered why it works and I don't think I have ever heard a proper explanation - it's always "it just works", no more. So my only intention has been to show, that playing minor pentatonic over a standard blues progression actually fits theory, and no rules are broken by doing so, and I think, I have done that. It requires, that we accept playing #9's instead of b3rd's and accept that we bend the rules when naming the notes - otherwise we would have 7 names for just 5 notes, and that's not practical when putting them together in a scale.
 
Momantai

Momantai

Red nose, red guitar
In short: the rules are not absolute.(y)
And I’m glad they are not because I break them all the time. :)
 
david moon

david moon

Attempting the Blues
Bolar said:
Exactly. And if you take the root & the 7th from each chord and put them together, you come up with the same scale. So when sticking to the minor pentatonic scale, we aren't playing any 3rd's at all.
Click to expand...
So in key of C
Root and 7th C Bb
In F F and Eb
in G G and F

so reordering

C Eb F G Bb

voila the minor pentatonic
 
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