These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Despite all the pretentiousness, there's still some good stuff that can be found on the band's first five albums, such as "The Barbarian", "Tarkus", "The Curse of Baba Yaga", "The Endless Enigma" and, most definitely, "First Impression, Part 2" of Karn Evil 9 ("Welcome Back, My Friends to the Show that never ends!")
Excerpts from "First Impression, Part 2" have even been used for the theme song and incidental music of BBC Television's prime-time show "The Generation Game" — though not the bit about "seven virgins and a mule", obviously.
Hell Is That Noise: "Toccata," most definitely. A prog version of a twentieth century composition that features strong discontinuity, dissonance, and Sensory Abuse. One of ELP's more frightening recordings. It's also so very much Creepy Awesome.
Emerson actually played an early version of the "Toccata" to composer Alberto Ginastera, who praised it as "diabolical" and commended its creepiness, largely since the "Toccata" had been written to be terrifying in the first place.
Narm Charm: "Lucky Man". Yes, the lyrics are simplistic and naive (it was written by a twelve-year-old Greg Lake). Yes, the guitar and vocals are pretty. And yes, it's pretty sadnonetheless.
Nightmare Fuel: On the one hand, a lot of ELP's attempts at this come across as Nightmare Retardant. On the other, they could pull it off when they tried, as seen with "The Barbarian", "Toccata", possibly "Knife Edge" and maybe Keith Emerson's distorted, Dalek-like computer voice at the end of "Karn Evil 9".