what i think we need here is the definition of what progressive rock music is
prog rock/metal/whatever is typically in a thrucomposed form, as in not a typical verse-chorus, or A-B-A form, but rather an A-B-C-D type form. prog also strays from the main idea of the music, usually going off in a completely different direction, the transfer from the first growled section in deliverance to the first clean section. prog also uses alot of exploration musically, as in the solos are usually off the wall, while still adding to the music. the name comes from the fact that the music progress from a to b to c, instead of a to b, back to a, then b again. i would would consider damnation prog because of the intense musical exploration of the album, but it also has a lot of psychedilica to it, like pink floyd type stuff, it has that soothing ambience that i could imagine being great to get stoned to.