Without question, Intronaut deserves considerable credit for their creativity on this album. Without truly straying away from their roots, the band has created a progressive/post-metal masterpiece unlike anything I have ever heard before. Prehistoricisms, as a whole, is an outstanding accomplishment and is quite certainly the band's strongest release to date.
I'm kind of a sucker for instrumental intro tracks, so I was very pleased with how "Primordial Soup" set the tone for the album. The track has fantastic dark resonance. It's atmospheric without hitting the post-metal pitfall of overdoing that atmospheric elements. Perhaps most importantly, it's very brief, running at just under a minute and a half. It sticks around for just enough time to build up the album's tone before moving on to the real core.
From "The Literal Black Cloud" on out, the album takes the listener on a very bizarre trip. "The Literal Black Cloud", in particular, is unlike any other previous song in the band's catalog in that it successfully fuses slow, mellow progression with harsh elements more typical of heavier genres of metal. Intronaut's previous full-length album, Void, was noteworthy for being chaotic and laced with segments reminiscent of groove metal or death metal. Here, on Prehistoricisms, those chaotic elements are still very much in use, but they are used much less frequently and with great control. All that being said, "The Literal Black Cloud" is a superb opening track and is one of the best on the album. It exemplifies Intronaut's new approach to songwriting, fusing the more notable elements of their older style with more traditional elements of progressive metal, resulting in a completely new sound.
The middle tracks of the album are best characterized by their unpredictability. Dark, mellow interludes give way to wild, frantic, growling segments. Experimentation runs amok, just as one would hope. The title track has perhaps the strangest introduction and main theme that I've ever heard. The bass line and main riff to the track are unsettling in an unusual way, and the song is just all over the place, featuring the albums most abrupt changes from mellow to fierce, and sometimes both simultaneously. The riff starting around three and a half minutes through the track is superb. It's simple, but very effective, and in clever contrast with the other sections of the song.
"Any Port" is a personal favorite of mine, my testimonial to it's greatness that I often find myself absentmindedly humming the introductory bass line. On that note, it's worth acknowledging the outstanding bass work on this album. In every song, there is a standout part for the bass, be it obvious in the form of a breakdown or subtle in the form of a great underlying line. "Any Port" is probably the best song on the album for the bass, however the breakdown that closes out "Australopithecus" is also fantastic, regardless of its simplicity.
The real monster of the album is the final track, "The Reptilian Brain", which is a sixteen-minute instrumental with five movements, humorously titled "Sleep / Eat / *** / Fight / ***". It's the album's most atmospheric track, and those atmospherics are executed exceptionally well. "Sleep" is an interesting experiment into exotic territory, featuring what I would ignorantly call a "tropical" sound. The percussion is excellent and fitting, using an instrument that I imagine is reminiscent of a set of bongos for the first few minutes. "Eat" flows beautifully from "Sleep". The transition is seamless and natural, with a simple change of pace and development of themes set forth in the previous movement. Best of all, I think it's really catchy, and it's another section of the album I find myself humming.
"The Reptilian Brain" is also notable for its incorporation of funk-like elements, to a lesser extent in "Eat" and to a significant extent in "***". In true oddball fashion, the album closes with what I would describe as sounding like 1970's psychedelic music. It's peculiar, but it flows seamlessly and it fits the musical themes set forth throughout the album. That particular trend is one of the things that makes this such a strong album in my mind. This is not a concept album, to be sure, and never does the band reuse any material from previous tracks, but there are still recurring themes. Musically, all of the tracks are connected via tone and style, which makes the album truly a cohesive whole, which is exactly what a seasoned progressive metal fan would hope to hear.
Highlights: The Literal Black Cloud, Any Port, The Reptilian Brain