I was really prepared to hate this, and frankly it took a little bit of listening to it before my hackles went down, but eventually I got over it and started to like it for what it is. 'Circadian Rhythm' is exactly the sort of thing I don't like in metal: turgid, a bit too ambitious and openly multifaceted in style, more than a little bit proggy- but I can't lie, the band actually goes somewhere with it. This album really sounds like a group of pretty talented musicians making a desperate bid towards making a really great album where a merely competent one would have sufficed, and it shows: it doesn't end up being great, but it is very good, and ends up being a perfect example of the sort of album most prog-minded metal bands should be shooting for.
This isn't really prog in the Dream Theater sense as much as a more general concept of 'progressive'. Thurisaz is, to some degree, a 'progressive' black/death metal band (or maybe that weird term 'dark metal' would apply here). This means that they play at a variety of tempos, use synths, have clean vocals here and there, bring out occasional esoteric folk influences, and in general sound like they're trying pretty hard to impress you with their sheer variation. It ends up sounding like a big, overwrought rock album more than a metal one a lot of the time- the exact way they go about making this 'progressive' sounds more like the way a rock band would do it than a metal band, considering that technical skill in and of itself isn't really emphasized much at all. Instead of shredding, we get songs with a whole lot of parts: blasting parts, slow, atmospheric parts, acoustic parts, and even ambient parts. Clearly there's an attempt at high art afoot.
While a comparison to Opeth in fits and starts isn't entirely without merit, this really sounds a lot more like overgrown traditional metal- think Savatage listening to later Emperor. While this has the trappings of extreme metal- occasional blasts, harsh vocals, etc.- it doesn't really feel like an extreme metal album so much as something from the '70s updated significantly. The bulk of the music on this record operates at a lurching midpace, giving the synths, vocals, and strings lots of room to move around and breathe. Most of the album is based off multiple, interplaying melodies- typically between the synths and... more synths, or sometimes the clean vocals, but the electric guitars are typically placed in a supporting role except in the most obviously metallic moments, riddled with blasts and double bass. Thurisaz is very good at instructing you as to what you're supposed to be listening to throughout the album. Like a painter guiding the viewer's eye, they emphasize one instrument, then another. It's an album full of leads with accompanying instrumentation in the background, really.
The trappings of all this might bring to mind something pretty pretentious and a little too precious for its own good- yeah, that's pretty accurate. But those things are really only problematic when the band is BAD at what they do, and the sheer professionalism of Thurisaz makes up for their lack of amateurish charm. A track like 'Fading Dreams' is an absurdly well constructed prog rock track for something that appears on an album that also includes blast beats and tremolo riffs. Oddly enough, the band never really seems uncomfortable with what they're doing- while a lot of bands of this nature tend to really sound like prog rockers who add extremity for the sake of it, Thurisaz sound pretty settled in both extreme and restrained modes. This all adds up to a very organic listening experience, and a good alternative to the more obvious and overstated prog acts out there in the metal scene. It really won't satisfy anyone looking for wild displays of virtuosic instrumentation or ostentatiously self-aware songwriting, but it's a clever album that still manages to pack good riffs and songwriting into its overtly prog construction.
I can't particularly describe a lot of this music as memorable, but it's a good ride while it lasts. 'Circadian Rhythms' is an album distinctly designed to be consumed as a whole, and it works well with the ebb and flow of distinct styles and tracks organically working through the album. It's not an extremely deep listen and it's not overtly emotionally affecting, but in sheer craftsmanship, Thurisaz have outdone themselves. Very good for prospective songwriters and musicians to listen to, and pretty good for pure listeners as well. Your money won't be wasted.