Theory Question About Blues

Hello Mike,

Let's take the an example of 12 bar blues in key of A. The I, IV, V chord usually played is A7, D7, and E7 respectively, and many things I read say you should solo/improvise over the 12 bar blues using A minor pentatonic, but the key is in A major. Why wouldn't A major pentatonic be a better choice. Also, why do they often play the I and IV chord as a dominant 7 chord vs a major 7 chord? If I wanted to stay with all the notes in the key of A I should play the I and IV chord as a major 7 and solo with the major pentatonic or majaor scale. Anly clarification would be appreciated.

[br]Regards,

Joseph

PS this is the Joseph who used to take your video group lessons before they cancelled.

Hey Joseph!!! Hope you’re doing well, and thanks for your question.

[br]Typically, the bluesy sound comes from the mixing of both the major and minor third (notes) with a minor seventh - so this presents a bit of a grey area when trying to explain the theory.

[br]First, let’s spell out the notes in a dominant 7th chord: root, major third, fifth, and minor seventh. So right away, we’ve got a note from the major scale mixed with a note from the minor scale.

[br]When we play over a blues progression that uses dominant chords, it sounds good and “bluesy” to mix the major and minor 3rds. A usual example is when we put a bluesy bend on the minor 3rd note - we are bending it up to the major 3rd. This is just one of the hallmarks of the sound of the blues. The minor pentatonic scale gets us that “built in” sound, and we can either bend up to the major third note, or simply add it to the scale. The minor pentatonic scale also contains a minor seventh note, so that works out nicely.

[br]Generally, it doesn’t sound as good to mix the major 7th in there, so you’re better to stick with the minor 7 (or b7) note.

[br]You could also use the “Blues Scale” which is the minor pentatonic with an added minor 5th (or b5) note. This also gives a very bluesy sound.

[br]As for using the major pentatonic over the dominant 7th chord progression - yes, you can do this!! It gives a slightly different sound - a bit brighter, but still bluesy. In fact, we often switch between using the minor and major pentatonic scales when improvising over a blues.

[br]In the case of a Minor Blues - which uses Im IVm and Vm chords -- you’d want to stick with minor pentatonic or the minor scale for it to sound right.

[br]I hope this helps!! Let me know how it goes!

Mike

Mike,

Thanks for the explanation! That helps a lot.

[br]Joseph

Originally Posted by: jwm3320Let's take the an example of 12 bar blues in key of A. The I, IV, V chord usually played is A7, D7, and E7 respectively, and many things I read say you should solo/improvise over the 12 bar blues using A minor pentatonic, but the key is in A major. Why wouldn't A major pentatonic be a better choice. Also, why do they often play the I and IV chord as a dominant 7 chord vs a major 7 chord?

Hey, Joseph. In addition to Mike's excellent answer, I have a few tutorials aimed exactly at your question. This one in particular covers how & why mixing major & minor notes is a key characteristic of the blues.

https://www.guitartricks.com/tutorial.php?input=217

Hope that helps!

Thanks Christopher!

Originally Posted by: ChristopherSchlegel

Originally Posted by: jwm3320Let's take the an example of 12 bar blues in key of A. The I, IV, V chord usually played is A7, D7, and E7 respectively, and many things I read say you should solo/improvise over the 12 bar blues using A minor pentatonic, but the key is in A major. Why wouldn't A major pentatonic be a better choice. Also, why do they often play the I and IV chord as a dominant 7 chord vs a major 7 chord?

Hey, Joseph. In addition to Mike's excellent answer, I have a few tutorials aimed exactly at your question. This one in particular covers how & why mixing major & minor notes is a key characteristic of the blues.

https://www.guitartricks.com/tutorial.php?input=217

Hope that helps!