Not that long ago, I was giving an off the cuff lesson to a friend who asked about blues soloing. I just said to play the minor pentatonic scale. I immediately regretted saying that. It was a pat answer and I was guilty of doing something that I hated seeing in guitar instruction. I was reducing improvisation to the quick fix approach of scale theory.
When I was starting out learning to play music, I would read all the interviews and articles in magazines like Guitar Player or Downbeat, looking for the answer to the big question: What scales do you use? I was looking for the “Unified Field Theory of Improvisation”. A one size fits all approach that would suddenly make me sound like my musical heroes. What my experience has shown me is that such an approach is a fool’s quest. If it was just a matter of “If this, play this scale”, then we would all be musical heroes.
When you are improvising you are speaking a language. You are engaging in a conversation with the other musicians and with them, the listener. And as in speaking a language, different genres of music have their own vocabulary.  Simplifying playing blues (or jazz, rock, country, etc.) to just playing a scale is analogous to telling someone that once you learn the Cyrillic alphabet, you can speak Russian. This is not to say that there is no value in learning the minor pentatonic scale (or any other scale). We all need to learn our alphabet. It’s just one step in the process.
Listening and studying the playing of great musicians in many different genre of music, I’ve realized that they rarely stick to a single approach. Even blues musicians whose vocabulary were primarily based on the tonic minor pentatonic scale would often imply notes not found in that scale through the use of bends. In particular, a lot of guitarists would finger a minor third but bend it up to the major third when playing on the I chord. Other guitarists would just add the major third to the minor pentatonic scale patterns.
As I have mentioned in a previous post, I have been working on adapting my guitar vocabulary to the Stick guitar. As part of the process, I have been thinking about the evolution of my own approach to blues soloing. Initially, like almost everyone else, I started out with the tried and true minor pentatonic scale. After hearing bands like the Allman Brothers and The Grateful Dead, my playing began to incorporate the major pentatonic scale as well. In hindsight, I now realize now that my playing suffered from what I know now as one of the shortcomings of the whole “just play this scale” approach: By thinking in terms of scale patterns, you are not really aware of the changes you’re playing over. As a result, I found that my lines were often not emphasizing the right notes at the right time. Instead of telling a story, I was mumbling.
Then, by happy accident, I stumbled on the best thing to happen to my guitar playing: I began to play bass. When you play bass, part of your job is outlining the harmony. It also makes you really learn your arpeggios throughout the neck.  When I went back to playing the blues on guitar, my lines reflected the time I spent playing bass and began to be heavily based on chord arpeggios. As I had become heavily involved with jazz in that time, I didn’t think that this was a bad thing. After all, learning to “play the changes” is essential to jazz improvisation. And developing the ability to play the changes, I believe, gives one the skill to really control what colors you can add to your lines. But as my playing became more arpeggio based, I also noticed that my playing began to lose the more traditional blues flavor that you would hear in a solo by someone like Freddy King and I didn’t want to give that up. I realized that I needed to better integrate my straight blues playing with my jazz playing.
So now, when I play the blues (or anything else for that matter), I use it all. I might start by playing the tonic minor pentatonic scale but add the major third of the chord I’m playing over. Or play the sixth or a ninth of the chord with the tonic blues scale. I might start by thinking mixolydian mode but change to playing the tonic blues scale along the way and then change to playing the minor pentatonic of the chord I’m on at the moment. I might want to emphasis the major tone colors of the chord or choose to go with a minor scale. And then there is the option of using what is referred to as “altered” tones. These are the notes that are not diatonic to the chord. Examples of altered tones are flat ninths (b9), sharp nine (#9),  sharp eleventh (#11) and flat thirteenth (b13). There are points in the standard I-IV-V blues progressing where you have a couple of V-I chord resolutions. One point occurs in bars four and five. In the key of C, that would be C to F. You may think of it as I to IV in C but it’s also V to I in F. The V to I chord resolution is one of the touchstones of standard harmony. It’s the concept of musical tension and release at it’s most basic. By playing altered chord tones over the V chord, you are ramping up the tension in the harmony that is released when you resolve to the I chord. Jazz blues chord progressions build in even more V-I resolutions than your traditional blues progression, giving one a lot of opportunities to add these chromatic colors to your lines. And there are passing notes, chromatic targeting of chord tones, superimposing one chord over another, substituting one chord for another and so on. I hope to discuss these approaches in more detail in future posts.
Getting a handle on all this stuff can be overwhelming. To truly attempt to master the art of improvisation is a long term pursuit. If I had the chance thirty some odd years ago to ask the future me what scales do I use, I would have to say just one, the chromatic scale. By learning that there is no single approach to soloing, you realize that all the notes are available to you to use as you see fit.

It always helps to hear how the Masters do it. I can think of few better examples than the late great Michael Bloomfield. Enjoy.