A pig’s squeal is centered roughly around 4,000 HZ (for real; love the internet) Hmmmm!......I think it may be time for new tubes in your line stage 😉. Seriously, like acman3 said, listen again; at least for the 60 seconds. It’s worth it. Try it again:
https://m.youtube.com/watch?v=-75nlrqEjWA**** "How do you come up with something like that?" ****
Who knows? However, one has to understand the culture to get it. And I think part of the answer may be found in why Miles said what he said about Hermeto and what we know about Miles. IOW, a no boundaries, “sky’s the limit” approach to the creative process. There are, in fact, some people on this planet that hear music, or the potential for music, in just about any and every sound and thing imaginable; and have an extremely uncompromising attitude about this idea and their art in general. Hermeto is one of the few that can also back up their way-out-there notions with extreme ability and skill in the conventional.
Btw, I went to an Hermeto concert back in the 80’s here in NYC. I heard some of the most unbelievably virtuosic and intricate compositions for a “jazz” band imaginable. Right off the bat one could tell that Hermeto was annoyed that there were some in the audience who weren’t listening and were there just to socialize. Half way through the third tune he waved the band out and they walked off the stage. I didn’t blame them.
For anyone interested in learning about this very unusual musician:
https://m.youtube.com/watch?v=9hb_Q3VCViI