Barney is NOT playing blues under a more strict definition. Barney plays blues much like a piano player plays blues, which at best is a stretch calling it blues. And it's why piano is not for me. What Barney is not doing is giving his blues variable pitch. He doesn't bend into the sweet spots that just sing. First off the guitar is out of tune by it's construct, same with the piano. But the tuning on the guitar is adjustable by pressure and micro bending. The guitar tuning is called 12edo, that simply means divide the octave into 12 equal distance parts (talking pitch distances not the necks physical length because frets get closer but we agree that from one fret to the next is a half step. Then there is what is called Just Intonation. This is purely in tune. It doesn't match up to 12edo exactly, close but some notes are a little off, for example 3rd is around 17 cents too sharp for just intonation. Also the flat 3rd is too flat and in the blues we "sweeten" the tuning by bending a micro end up. That is bending from the too flat note the guitar offers into Just Intonation, or JI. Anyone that has listened to Black Dog by Led Zeppelin has heard this bend, it happens on the 6th note of the main riff and happens a couple more times. The riff is laden with these elements that we call blues, even though it's a rock song. Spoonful is another classic song that uses the too flat 3rd and bending up to the sweet JI flat 3rd, There are other tones that help define that blues sound, I just talked about the 3rd. Barney was not shooting for these blues sounds, he used seven note scales for the most part, very diatonic, no bending. This is why in this thread I've been advocating for the pents and their blues qualities to be the heart and soul of real blues, the emotions the blues stirs up in us. By it's nature, to be Mixolydian it needs to be micro bend free and that sucks on our guitars, we want to bend, we desire to microbend every chance we get on the fretboard when playing blues. We also like to hear non blues music such as in many jazz, folk and pop tunes. Blues inflections don't always work with this kind of music. Strictly Diatonic.