#1
I seem to have confused myself looking into the theory behind the blues. I know several people are going to rely blues isn't about theory, its about feel etc, but there is theory still there!

Anyway, my problem is this, say I was playing 12 bar blues in the key of A. Now your standard progression is I I I I IV IV I I IV IV V IV I V. These are all major chords, so why do people tell me to use the A minor pentatonic to solo over this, surely this would mean I'm soloing in A minor over an A major backing. Shouldn't I use F# minor instead, the relative minor of A major?
Wouldn't playing A minor Pentatonic mean I was playing in the key of C and therefore use a C F G pattern for the background?

I read something about using both major and minor scales together in licks and double stops help give a "bluesy" sound, is this why I should use A minor instead of F# minor?
The article (was one this site, but can't remember which) also said that if I was in the key of A, then playing A minor, D minor or E minor pentatonics would all be fine too, it just doesn't make sense.

Anyone care to clarify?
#2
If it's in A, you don't use F# anything, because it's in A.

It's a stylistic feature of the blues to use both the minor pentatonic and major pentatonic in a major blues song.
#3
So if I played the f# minor pentatonic instead, would it just sound "normal" instead of bluesy as it would mean I was playing entirely in the key of A major. If so, this would still sound right. I'm guessing i'd be free to just move between the two scales (almost) as I please, as long as I don't include the ii or vi chords? In which case I would need to use the f# minor entirely, correct?
#4
So in a major blues you have (let's do this in C, for readability):

I - C (C E G)
IV - F (F A C)
V - G (G B D)

Playing the C major pentatonic (C D E G A) over that, you have:
  • the 1, 3 and 5 of the I chord
  • the 3 and 5 of the IV chord
  • the 1 and 5 of the V chord


Playing the C minor pentatonic (C Eb F G Bb), you have:
  • the 1 and 5 of the I chord, plus the b7 that would make it a dominant 7th chord, plus the b3 that can be used to make a false relation against the 3 in the major chord, which has a bluesy sound
  • the 1 and 5 of the IV chord, plus the b7 and 9 which could make a 9th chord as well as a 7th
  • the 1 of the V chord, plus the b7 which could sketch a dominant 7th chord, plus the b3 that can make another false relation



There's nothing to stop you using both scales, plus the b5 for effect.
Last edited by blue_strat at Mar 17, 2011,
#5
I think I understand why I can do it now. My aim is to be able to re-write songs in a more bluesy feel. I'm a bit of a lousy singer, but even worse songwriter, so I figured this would be a good way to get into writing my own songs without having to start from scratch.
The first song I'm planning on using is Wonderful Tonight by Clapton, since this is just a I V IV V pattern in the key of G, i can use g minor pentatonic the entire way through, right?

Thanks for your help guys!
#6
depending on the type of sound that you want, you can play a blues scale starting on any degree of the tonic chord. For example if you're in the key of A your basic A7 chord will consist of A, C#, E and G. Depending on whether you the play A blues, C# blues, E blues, or G blues scales, this will provide you with different sounds/tensions etc to make for more interesting listening rather than being diatonic all the time.
If you want to play an F# blues/pentatonic scale over and A chord I'd say why not! since F# is the 13 (if I'm not mistaken) degree of an A chord. at the end of the day it's what sounds good to you - sound is subjective.
#7
Quote by blue_strat
So in a major blues you have (let's do this in C, for readability):

I - C (C E G)
IV - F (F A C)
V - G (G B D)

Playing the C major pentatonic (C D E G A) over that, you have:
  • the 1, 3 and 5 of the I chord
  • the 3 and 5 of the IV chord
  • the 1 and 5 of the V chord


Playing the C minor pentatonic (C Eb F G Bb), you have:
  • the 1 and 5 of the I chord, plus the b7 that would make it a dominant 7th chord, plus the b3 that can be used to make a false relation against the 3 in the major chord, which has a bluesy sound
  • the 1 and 5 of the IV chord, plus the b7 and 9 which could make a 9th chord as well as a 7th
  • the 1 of the V chord, plus the b7 which could sketch a dominant 7th chord, plus the b3 that can make another false relation



There's nothing to stop you using both scales, plus the b5 for effect.
Great explanation.
Only play what you hear. If you don’t hear anything, don’t play anything.
-Chick Corea