Style: Progressive rock, math rock (Instrumental)
Recommended for fans of:  King Crimson, The Mars Volta, Mulatu Astatke, Caravan, Maruja
Country: United Kingdom
Release date: 10 April 2026

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We lean toward covering prog metal—as opposed to prog rock—at The Progressive Subway.¹ But who can really blame us when it seems like the average prog rock album is uninspired, stealing ideas last fresh in the 70s? Every other prog rock review we pen here talks about how the genre is stagnant, but does it have to be that way? Brighton-based prog rock quartet Poly-Math try to spin that narrative. 

Poly-Math take influence from the classic prog sound—particularly informed by the jazzy Canterbury scene, as well as avant weirdos like King Crimson, The Mars Volta, and the RPI (Italian prog) world—but the record is also so diverse and fresh as to operate in a separate paradigm entirely. The album title, taken from a book by theoretical physicist Sean Carroll, provides a clear analogy. Something Deeply Hidden is the quantum mechanics of prog—sometimes, and for the average situation, Newtonian physics gets the job done—but a better, modern interpretation of the model exists for extreme cases. Something Deeply Hidden is multifaceted, drawing from a wide range of musical influences, including Ethio-jazz, math rock, psychedelia, post-rock, and prog metal; at times, each instrumentalist provides influence from a different one of these styles at the same time. Carroll’s book argues for the many-worlds interpretation of quantum physics—that all possible outcomes of quantum measurements are physically realized in a sort of multiverse—and Poly-Math’s sleek prog rock is the sonic embodiment of the theory.

Poly-Math really love Poly-Rhythm, playing a full mosaic of beats and times across a track. Laying down unreasonably nasty grooves with the fattest tone I’ve heard in a hot minute, bassist Joe Branton routinely steals the show with his impeccable grooves, despite rarely intentionally being the flashiest instrumentalist on a track. On “No Such Thing As Now,” his mischievous bassline provides the structure for knotted guitar parts and micro buildups to blossom, as they follow his cue to explode once he raises the key around the midpoint. His rhythm section partner, Chris Woollison on drums, is an expressive performer, fitting various moods with a wide array of percussion instruments—from the bongos propelling “The Universe as Engine” and “Terror Management Theory” to the maracas spicing up the vintage prog mellotron at the start of “No Such Thing as Now” to the guiro making the latter half of “One / Two / Three / Four Body Problem” seem danceable despite the atonality and freaky polyrhythms—I swear one part in the middle is a 30:31 polyrhythm or something ridiculous.

Of course, no band intrigues by rhythm alone (Meshuggah fans get rekt). Fortunately, keyboardist Josh Gesner and guitarist Tim Walters splash color on Something Deeply Hidden. The wild synths that begin “Spectral Dis / Order” sound like they could be from an industrial Super Mario Galaxy stage; the Ethio-jazz-style keyboard solo around 5:00 into “Terror Management Theory” is incredibly funky; the synths are an effervescent, prog electronica presence in “The Universe as an Engine”; and in general, Gesner fills out any negative space in the sound, adding density to the album, like a non-orchestrated version of All Traps on Earth. And Walters also has oodles of highlights. Aside from falling back on a jangly math rock tone I don’t love, Walters plays immaculately and has mastered writing complicated riffs without feeling like he’s forcing virtuosity. He lays down prog metal-esque riffs—one of the best examples is his weaving between expressive percussion during the climax of “One / Two / Three / Four Body Problem”—just as easily as he can play a Santana-esque fusion solo. He also navigates both melodic and dissonant sections as convincingly as anybody. 

Poly-Math are efficient with their runtimes, formulating entire post-rock buildups in only a couple minutes, improving upon the average post-rock band’s ten minutes—my favorite is the total strip tease ending of “The Universe as Engine,” in which the track builds to a cacophonous peak before cutting. The only wasted space is during the frustratingly long three minutes of superfluous ambience closing out “Euthyphro Dilemma.” Finally, while Poly-Math extract as much as they can out of their four-piece instrumental lineup, they’re missing an intangible signature or characteristic; polyrhythms are cool, but they alone don’t make enough of an identity—perhaps the lack of vocalist bites Poly-Math in this regard.

With extremely refined performances, dynamic songwriting, and a vibe as cool as quantum physics, Something Deeply Hidden is total Prog Subway-core. Poly-Math prove that there is innovative and exciting progressive rock out there; Something Deeply Hidden is a hidden gem that I’m glad I can share with our readers as a reminder that good prog exists all across the heaviness spectrum.

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Recommended tracks: One / Two / Three / Four Body Problem, No Such Thing as Now, Spectral Dis / Order
You may also like: All Traps on Earth, Ukandanz, Cleft
Final verdict: 7.5/10

Related links: Bandcamp | Facebook | Instagram

Label: independent

Poly-Math is:
– Joe Branton – Bass
– Josh Gesner – Keys
– Tim Walters – Guitar
– Chris Woollison – Drums
With guests:
– Ben Harris (additional guitar on “Terror Management Theory”)

1.  If you’re a prog rock fan reading this who fancies pursuing a reviewing hobby, email us. ↩︎