A lot.
At least to me. I mean, I could try to listen just "as an interested musician" Which I honestly tried.... 
Yeah, me too. Listened to "Slayer": here's what I heard: it's music since it's definitely organized sound. Incessant, unvarying beat -- pretty hypnotic, but, then so is that jackhammer hammering away on the street below. Lead singer either has nodes on his vocal cords by now or is the process of getting them. Really rancid tone production there, but I suppose it's meant to evoke, what, rage? Don't hear anything but the most basic chord progressions. Pretty static. VERY loud, which, I guess, keeps it from becoming boring -- as long as you're on Exstasy or some other party drug. Can't imagine tolerating it for very long without major drugs.
"Hypocrisy -- The Final Chapter". Listened to two minutes of that. VERY moody, theatrical staging there. Great lighting. And, of course, anyone naked from the waist up attracts SOME attention. Are there lyrics here? Couldn't hear them, but heard some sort of background, ominous incantation going on. I only heard two pitches in the guitar line -- a pitch, raised a half-step, then back down again. Over and over. Not a lot of variety. Also, VERY loud. Auditors seem hypnotized, as always, by the pounding, relentless beat. I guess drugs make it better.
Can anyone enlighten me about this music? I like pop. Who doesn't? Much of it is terrific. But this? I don't get it. Sounds sophomoric and pompous. Adolescent angst. Maybe that's the point and I'm too old to hear it.
And why are the song titles and band names so, well, arch and pretentious? Whatever happened to names like Gladys Knight and The Pips? Simple, direct -- to match the music they made.