Joe Satriani

“When you're a teacher, you realize that you have to clearly encapsulate some unrelated technical ideas that you take for granted and understand and put them into words so someone else will understand them.”
― Joe Satriani, Strange Beautiful Music: A Musical Memoir

“pitch axis theory, which I learned in high school from my music teacher Bill Westcott. It is a compositional technique that was actually developed at the turn of the last century, so this is something that had been around for a long time. I remember Bill saying, "I'm going to teach you this very cool compositional technique," and he sat me down at the piano, and he went, "Watch this: I'll hold this C bass note, and then I play these chords, and each chord will put me in a different key, but it will sound like C 'something' to you . . ." I was fascinated by it, because I thought, "That is the sound I'm hearing in my head." To me it sounded very "rock," because rock songs don't travel around in too many keys, and it was the antithesis of the modern pop music that had been around for fifty years. It was the total opposite of most commercial jazz, but not all jazz, as I learned when I started really listening closely to modern jazz. I realized, "Wow, John Coltrane is using pitch axis theory. Not only is he doing that, but he’s going beyond it with his 'sheets of sound' approach," where in addition to building modes in different keys off of one bass note, he was building modes off of notes outside the key structure as well. He had taken it a step further. But that’s not what I was looking for, except for in a song like "The Enigmatic," which has that sort of complete atonal-meetspsycho melodic approach. I was more interested in using the pitch axis where you really could identify with one key bass note, in a rock and R&B sort of fashion. Then all the chords that you put on top would basically put you in different keys. So on Not of This Earth, you have these pounding E eighth notes on the bass, and your audience says, "Okay, we're in the key of E." But the chords on top are saying, "E Lydian, E Minor, E Lydian, E Mixolydian in cyclical form." And I thought, "Well, this gives me great melodic opportunities, I'm not stuck with just the seven notes of one key. I've got seven notes for every different key that I apply on top of this bass note." And I just love that sound, so I applied it to quite a lot of my music.”
― Joe Satriani, Strange Beautiful Music: A Musical Memoir