This is a concept album based on Joe Haldeman's The Forever War book. I've heard a lot of concept albums and usually find the conceit falls apart quickly, making the music and lyrics forced and awkward. Not so with Infernal Machine. In fact, this is one of the most successful and enjoyable concept albums I've heard, on par with and sometimes besting Pink Floyd's overlong The Wall.The music (and artwork) is rooted in 1970s progressive rock (more King Crimson than ELP), with influences from psychedelia, movie soundtracks metal, stoner rock, complete with Mellotron, reverbed-out surf guitar, and phased vocals. Odd time signatures are present but not overwhelming; more Rush than Yes. "Tracks Over Carcosa" is a standout example: the best song on the record, it evokes the best of 1970s European film noir soundtracks (e.g. Ennio Morricone's more angular work like Fear Over The City or Dario Argento movies).This is a terrific, original album that's both firmly rooted in the 70s and timeless. Highly recommended.