A progressive album that moves downward, The Ocean’s sixth album, Pelagial, had originally been planned as an instrumental movement, one in which the music would indicate for listeners some aural odyssey, (oceanic travel in this case). The post-metal sextet eventually included singer Loïc Rossetti, (who’d been initially excluded from the project for health reasons), and lyrics were developed referencing the Andrey Tarkovsky's movie, Stalker. The songs are broken out to represent every phase of the journey, beginning at the water’s surface and ending in its depths. Next to the story Mastodon conceived for Crack The Skye, Pelagial’s concept isn’t that difficult to digest.

However, Pelagial is a vexing listen, one that both fully demonstrates the ability with which The Ocean can execute its ambition, but also questions whether or not the post-metal and/or progressive thing has lost its luster. Some things you come to expect with an album built from concepts and chapters, (Rush, Yes, Giant Squid, Mastodon…etc.), like its introduction with a piano ballad, like its calculated asymmetry, like all the time signatures in its employ. Pelagial could in fact be one of the best albums of its ilk, but I only felt jaded listening to it, able to pull certain comparisons to other progressive and/or post-metal bands which summed up my complete indifference. Unfair? Yes, which is why the album is so frustrating: It has the power to impress, but not necessarily compel in any distinguishable way.

Having said that, I can’t imagine that its instrumental counterpart would be a better listen, as I don’t think the music could carry the concept by itself. Both versions are available, which means The Ocean either couldn’t decide how best to complete its vision, or figured they could capitalize.

Although Pelagial inspired more cynicism than amazement, I can’t deny that it’s well composed and, at times, beautiful. The melodies that introduce the first vocal offering, “Mesopelagic: The Uncanny,” are interestingly folk-based until the hook takes an almost pop turn and the song acquires nü swagger that’s both catchy and disconcerting.

While the "Bathyalpelagic" series, (“Impasses,” “The Wish in Dreams” and “Disequillibrated”), generates a block of over-the-top power jams based in the album’s musical odyssey and a boastful degree of six-string intricacy, (“The Wish in Dreams,” in particular, could’ve been lifted directly from Mastodon’s Blood Mountain), Pelagial is at its strongest at the halfway mark. Despite the fact that thematic riffs are recycled throughout the album, (appropriately, as Pelagial is after all a unified concept), there’s enough variation in tone and tempo so as not to milk a singular motif. The transitions into “Abyssopelagic” (“Boundless Vasts” and “Signals of Anxiety”) and “Hadopelagic” (“Omen of the Deep” and “Let Them Believe”) are seamless, the drama growing darker, thicker, slower and increasingly more isolated. While “Let Them Believe” allows a melodic break from the murk, bowed instrumentation and fluttering piano keys dancing beneath the drifting guitar strings, it’s then fused with “Demersal: Cognitive Dissonance,” an off-time riff churn that leads into some of the album’s heaviest musical offerings. “Benthic: The Origin of Our Wishes” takes Pelagial’s thematic riff to its slowest, chunkiest pace, arpeggiated guitar notes cycling beneath the mire.

As The Ocean attempts its depths, the album-as-submersible conveys the supposed vastness of their concept, which is understood to keep expanding creatively undeterred by limitation. Quite the metaphor, albeit unintended. Instead, though, the band draws from what seems to be more of a narrow trough, currently drying up from being continually subsisted upon by other post-metal and progressive bands. While, the music’s no less remarkably conceived and performed, the ideas are waning. Pelagial’s largeness of scope sounds smaller than it should.