Just seeing this now - we’ve been swamped. I actually don’t know this tune, but it’s a cool riff and John does an awesome job with it.
As others have noted, this is a classic one-note-per-string arpeggio workout similar to what bluegrass crosspicking type lines. I do this sort of thing with wrist motion and of all the ways I can think of to do it, that’s the one that has the fewest moving parts. We do have a lesson doing these kinds of patterns with wrist motion right here:
We do have an older video that’s public on our YouTube channel that outlines the general concept of how the wrist motions work, and you can find that here:
We don’t really go into the step-by-step “how to” of it in that video, because we were still figuring that out. But the concept is sound and has proven to be (mostly!) correct as we’ve learned more.
As far as how John himself does this, it’s a little more complicated. There’s a short hand closeup right at the beginning of the live clip, and it looks like he’s using a mix of fingers, wrist, and forearm to do this. When it comes to players who learned these types of riffs by feel you will see lots and lots of idiosyncratic combinations of movements, so there are many ways to do this and they are all in some sense “correct”. We teach the wrist method because it’s the simplest to explain and teach. But if players want to experiment and come up with alternate ways there is certainly no shortage of possibilities if you’re willing to do some “discovery” on your own.
Great riff.