Sound Design on Trent Reznor and Atticus Ross's score, "The Vietnam War"

Hey! Not really on this sub a whole lot, but I'm desperate for answers as to the sound design Trent and Atticus did for this soundtrack. Particularly, on "What Comes Back" at 5:48. The wailing on what sounds to be a guitar (?) is incredibly difficult to replicate. I originally assumed it was just pinched harmonics that were then heavily processed, but now I'm thinking it could be a synth? Both? No idea. Knowing them, it's definitely something that was performed live for the recording, I just have no idea what they may have used. Anyone who knows their process better than I do have any ideas?

This soundtrack flies under the radar for a lot of people but it's incredible. Highly recommend watching the documentary series too; it'll change your life.