Some of these are harder and more abrasive than others:

King Crimson (really depends from album to album!)
Tool
Mastodon
Peter Gabriel’s first few solo albums.
Peter Gabriel-era Genesis
1970s-era Yes
Pink Floyd
Under the Sun
Enchant
The Mars Volta
Emerson, Lake and Palmer (avoid anything after “Brain Salad Surgery”!)
Spock’s Beard
Jethro…[Read more]