Definitely some kind of instrument/synth plugin. He’s a pretty digital guy, and a plugin/daw wizard. And to the weird fingerings and intervals, it’s because he writes in the DAW, and then has to back out how to play the parts on guitar. It’s why almost all of their newer music seems has such unusual guitar work.
Don't know for their early stuff, but Tim got his own Archetype plugin now, and use QuadCortex, both developed with NeuralDSP. I linked what I could find in a direct comment a couple min ago on this video. I'm not a musician, can't explain it all, sorry.
04.01.24 Hi there, Bud. Great reaction! No wonder why you were wondering what instrument they used in that opening. It's actually a saw blade, more commonly used in Norwegian pop music. Love from Norway ♥♥♥♥♥
As a Bavarian I'd have sworn it was an Alphorn recorded from a distance of 70 km, sampled and synthesized, but I may be wrong... - Seriously, don't know if you've seen it, Polyphia also released a "Making of G.O.A.T." video at the same time, in which he explains in depth how he did it... Peace and love from Bavaria!
In case you're interested, Polyphia released a "making of" video around the same time... in which he explains in depth how they did it and where that theme is from...
