Theory Question: Which blues scale over which key?

[mistertoast]

I know one answer to the question before I even ask: "Just try it and see what you like." But I like to know why these things work so I can be a bit more deliberate about the choices I make.

My current question is this:

If you're writing an instrument solo (or a vocal part) in a blues scale, what keys can you play it over?

I've heard a few answers, because I know that people do all kinds of things.

Let's assume that the music has chords I, IV, and V. All the notes in the chords are diatonic. The blues scale adds a flattened (blue) note that's not in the key. That's what makes it sound bluesy. It seems that by choosing the blues scale independent of the key the chords are in, you can place that blues note anywhere you like. For instance, maybe slide it up so that the blue note is the flatted seventh, then you can have it correspond with the bass of the bVII chord (which is commonly substituted for the diminished chord).

Another alternative would be to put the blue note on the tonic. Then you'd have a bunch of the blues scale non-diatonic to the chords being played. The song would probably sound discordant and unsettling.

Is anyone else interested in the stuff as a mental exercise? Or do you just "play?"

[BertKoor]

I'm sure most blues musicians just play. Not many of them are aware that "tonic" is something else than what the misses drinks with her gin.

I'd start for instance with the pentatonic blues scale in C (C Eb F, G, Bb C) and add whatever you need inbetween (also with pitch bend) for the occasion.

[Hink]

really all a blues scale is is just a minor pentatonic with an added diminished 5th...minor penatonic is 1, b3, 4 5 b7...blues scale 1, b3, 4, b5, 5, b7...I know it's an over simplified explanation

[mistertoast]

>>I'd start for instance with the pentatonic blues scale in C (C Eb F, G, Bb C) and add whatever you need inbetween (also with pitch bend) for the occasion.

Yeah, the nice thing about the blues scale is that around the blue note, anything microtonic works. Great for pitch bends.

Doesn't really answer my question though, which might have been poorly stated. Let me try again.

What different emotional effects, or what different "surprises," do you get as you vary the key of the chords versus the key of the blues scale you play over it?

[mistertoast]

>>really all a blues scale is is just a minor pentatonic with an added diminished 5th...minor penatonic is 1, b3, 4 5 b7...blues scale 1, b3, 4, b5, 5, b7...I know it's an over simplified explanation

yeah. The blues scale adds the bluesy note. My question is really about how you choose to place that extra note in relation to the key in which you're playing the chords.

My question was too esoteric, I think.

[BertKoor]

The solo should tell you a story, and so can go wherever the player feels it has to go. The rest of "orchestration" should support whatever mood the solo-payer is in. It's organic by nature.

Blues is the last genre that needs theoretical analysis. It needs to come from the heart, not from the mind. By doing that you drain out the soul, and emotional effects go down to zero.

[Hink]

The blues scale adds the bluesy note. My question is really about how you choose to place that extra note in relation to the key in which you're playing the chords.

I like BertKoor's answer, you don't "choose", it calls out to you...

[Peel]

Well, it isn't simply having a note outside the diatonic scale that makes it sound bluesy. The blue note(s) are just notes that are chosen for various harmonic or melodic reasons, but happen to lie outside diatonic harmony.
In a typical blues-rock style, the root of the lead scale is the root of the I. Here, the flat 3rd & (often) the flat 5th are typically the blue notes. That's why blues rock is sort of the lowest common denominator of modern music, the style that you most often hear musicians slipping into "faking" in those moments they can't find their inspiration.
In more rootsy blues styles, there are any number of blue notes, and they don't normally fall on the notes of the 12TET scale unless the instrument forces them to...
But yeah, I'm interested in this sort of thing

[mistertoast]

>>Blues is the last genre that needs theoretical analysis. It needs to come from the heart, not from the mind. By doing that you drain out the soul, and emotional effects go down to zero.

But I want to know WHY it works. I don't think anything is outside the realm of observation.

I'll grant that blues players are doing it by ear and raw talent. I can't be one of them, but I'm interested in their craft.

Skip James played most of his blues with a tuning of his guitar that he devised. He had a pretty good knowledge of what he was doing, I'd say.

[mistertoast]

The reason I asked is I was inspired by Ed Roseman's discussion of the blues scale in "Edly's Music Theory for Practical People."

"...By the way, notice that none of the thirds in the I, IV, and V chords, are present in the blues scale. Ah, more bluesy rubbing!"

"Finally, try using this C blues scale with the blues progression in Eb...."

It's just interesting to me what you can do with this blue note as you change the scale of the solo as opposed to the scale of the chords.

I was going to discuss playing the blues scale over various minor scales and modes. Glad I resisted.

[Hink]

>>Blues is the last genre that needs theoretical analysis. It needs to come from the heart, not from the mind. By doing that you drain out the soul, and emotional effects go down to zero.

But I want to know WHY it works. I don't think anything is outside the realm of observation.

I'll grant that blues players are doing it by ear and raw talent. I can't be one of them, but I'm interested in their craft.

Skip James played most of his blues with a tuning of his guitar that he devised. He had a pretty good knowledge of what he was doing, I'd say.

very few tunings are left to be devised...I use many tunings...but I tend to play minor tunings. A typical blues tuning is open DGDGBD, but Gm is DGDGBbD...another is Open A EAEAC#E, I tune to Am EAEACE (though Am tuning is raely seen in books and such on alternate tunings I hardly think I devised it) note that Gm is just a whole step below Am (I use it on my ax with 24 frets....gives me more range in a lower direction) but bot both are one half step on one string from the maj. Open E EBEG#BE is another popular blues tuning (though many players like SRV tuned it down a half step so open Eb is more accurate), but again I often tune it to the minor EBEGBE...notice how nice the top three strigs works out...having the natural open notes in your scales gives you an advantage of playing passages that otherwise would be difficult, it also gives "feel" to the solo...

[meeks]

very few tunings are left to be devised...

bahh...you haven't started switching strings around

Seriously, N tunings = N chords, am I correct in that assumption and if it is thats pretty numerous per say.

[nuffink]

I don't think you can be said to play a blues scale over a particular key. The current chord (a dominant seventh or substitute) sets the key of the moment and the blues scale based on that chord's root is used to play the melody. The overall key sets the root motion (traditionally I - I - I - I / IV - IV - I - I / V - IV - I - I) but not the chord types as in the diatonic system.
The characteristic blue third is (on stringed instruments) bent down towards a minor third and on fixed keyboards played as a "crushed" note (a minor third and major third played together). Particularly over the IV7 chord.
The same tecniques can be used for the blue fifth and seventh.

Yep, I know there are millions of exceptions.

[Jason Brian Merrill]

If the key is A, you can start off with the A pentatonic, which is basically a minor scale, you can add embellishments from the dorian mode -- but you can also play in major, and do the pentatonic shape on F#....

overall there are many notes that can fit into blues, if you make it fit (a la SRV) the major 6th and 9th can sound really good when played right --

[Hink]

very few tunings are left to be devised...

bahh...you haven't started switching strings around

Seriously, N tunings = N chords, am I correct in that assumption and if it is thats pretty numerous per say.

I didn't say "I" have used every tuning...and you're right about never changing strings around and there surely are many variations possible, but I think a lot have been tried...I'm sure many people are like me and try a variation. For instance I wrote a song that's in Dm, I tuned the guitar to Dm (DADFAD)...on my acoustic a while later I was messing around in Dm and thought "gee, that first A is just begging to be a G", I'm working on a song now with that tuning for my acoustic. Though I cannot find DGDFAD in other listing I hardly doubt I'm the first to try it...btw it works nicely..