You’re able to get so many timbres out of the instrument by how you pick and where you pick along the string. Talk about that.
You’ve hit on the most important thing about my trip. I’m absolutely obsessed with timbre and I’m much more concerned with how a note sounds than just having a stream of notes. I’m interested in the intimate relationship between how a person feels and how they translate that feeling with muscle action on the strings. What led me there is this: First of all, the National guitars have a wider dynamic range than any guitars, acoustic or electric. The difference between the softest and loudest touch is enormous. Secondly they have a huge range of timbre as you play along the string. Finally, I’ve steadfastly avoided using pickups my whole life. I play into a microphone and I don’t use any effects. I’m highly driven by the curiosity of my ears to get as much variety of sound as possible out of the thing. All microphones have a quality known as proximity effect, which is the closer you get, the more bass you get. And Nationals have this quality where the low end comes out of the grilles or the f-holes and the higher end comes out of the resonator area so, that gives me left and right. When I combine my hand touch on various parts of the strings and how I touch the strings, what I’ve got is this space in front of my guitar that’s pixilated in 3-dimensional pixels, each one is about a cubic half inch and each one throws up a different bar graph of EQ. Now I don’t think about this stuff as I’m playing. It’s too fast for thinking. I’m just like an animal—I hear and I move. That basically sums up my approach.

You’ll also pick behind the slide to get ghost notes.
There’s a whole negative fingerboard behind the slide. A lot of the notes are garbage but several of them are very nice.

You use a thumbpick and three fingerpicks, but not always for traditional fingerpicking. Can you describe your various techniques?
Basically I use the standard movements of fingerpicking, but I use them across all the strings. Nobody ever made a rule that you have to use one string per pick. I do two types of triplets that are really a signature of my sound. One is where I use thumb, middle, and index over and over again—either on one string, three different strings, or all six strings as a strum. Other times I hold my hand stiff and my thumb and index finger are like two sides of an imaginary flatpick and I’m moving my whole arm up and down and playing triplets. The faster I go the lighter I go—the least amount of blood sugar per muscle stroke, so to speak.

Which technique is on the fast picking in “Follow the Money”?
That’s thumb, middle, and index on one string. That technique was originally developed by this old Portuguese Hawaiian guy around 1910 named Frank Ferrera. Then Sol Hoopii, the great Hawaiian steel player, kind of took that technique and really launched it and that’s where I got it from. It’s hard to realize in the perspective of today’s music, but those early Hawaiian players were the Jimi Hendrixes of their day. They were making sounds that nobody had heard before and people flocked to them. That was around 1915. They were the first guitar heroes.

If you don’t use effects, how are you getting the wah wah sound in “How I Love That Woman”?
Think about what a wah wah is. It’s basically a treble control, removing treble. On a string, all the treble comes from the last few millimeters of the string, so all I’m doing is rolling the bar over the string at the bridge and playing on the “wrong” side of the string. I’m sort of choking off the high harmonics of the string the way a treble knob chokes off the high harmonics of music when you turn it down. It’s a very simple trick.

Where did you learn that?
I’m not going to make a lot of claims, but I will say that there are about a dozen sounds on an acoustic guitar that are mine, and that wah wah sound is mine. Several of the sounds you hear on this record I devised just by having curiosity and a lot of time with the guitar. I think of myself as kind of living out there on the edge in terms of exploring and finding sounds. The main thing I would try to encourage all guitar players to do is to free up their sense of curiosity, because the only limitation to any of this stuff is not being curious.

When people talk about early blues slide guitarists, they mention Robert Johnson, Blind Willie McTell, Mississippi Fred McDowell, etc. Who doesn’t get mentioned enough in your opinion?
Charley Patton is absolutely the most important Mississippi Delta blues guy. Without him, none of those guys would exist. I feel that his music is by far the most emotionally and rhythmically intense. It’s as far back as you can go in recorded history, almost all the way back to Africa. Robert Johnson, who gets a lot of attention, is sort of a musical grandson to Charley Patton, even though he recorded only a few years later. Patton is a little more challenging for people to listen to: the records are a little scratchy, the music  a little more syncopated. But it’s got a
lot more depth, subtlety, and interaction between guitar and voice. It’s really worth spending some time with. Even if the listener can’t really understand every word, if you want to really understand blues, put Charley Patton’s music on in the background of your life for several months and let his vocal phrases and timing and melodies wash over you until you start feeling him internally. If you’re going to be involved with Mississippi blues, Charley Patton is the man. You must start there. I say that emphatically.

Which term best describes what you do: guitarist, anthropologist, ethnomusicologist, or anarchist?
Sorry—I can’t pull those apart. I’m all of those things all the time, and I would add to that list musical physicist and neurologist. There’s a school of thought among certain musicians that if you think about something or study it, you ruin it. I don’t agree. I don’t believe in talent. I just believe in desire, and if the person who plays guitar has a strong desire, that’s almost all they need. That and some curiosity and a little respect for what came before. I realize as an anthropologist that music is older than language and that’s why language needs translation but music doesn’t. So what business am I in? I’m in the business of communicating feeling.