Since the late 1990s, Japan's Mono have stubbornly adhered to post-rock's basic aesthetics.

Though they've experimented with strings, keyboards, and various sounds and textures, all of their albums bear an unmistakable signature that combines formulaic dynamic strategies with wide tonal palettes and intimate, compressed melodic structures.

In Mono's music, rock is a way of examining and expressing emotional, psychological, and spiritual states.

Requiem for Hell is the quartet's ninth album.

It's a reunion with Steve Albini, their behind-the-boards collaborator from 2004's Walking Cloud and Deep Red Sky through 2009's Hymn to the Immortal Wind.

This is a back to basics affair, an attempt to sum up everywhere Mono has been, but it's also their noisiest record ever.

Opener "Death in Rebirth" is a companion piece to "Death and Reverse," their half of 2015's Transcendental split with Ocean.

It picks up where the earlier cut left off.

Takaakira Goto's and Hideki Suematsu's guitars introduce a minimal riff.

Drummer Yasunori Takada and bassist Tamaki Kunishi commence a hypnotic, martial vamp in response.

Ever increasing guitar layers get pasted onto the mix until it bleeds red with squalling distortion and feedback -- without forsaking an irresistible harmonic center.

The centerpiece is the set's 17-plus-minute epic title track.

Goto's sad guitar line is at the fore, while a softly played glockenspiel and ambient sound hover in the backdrop.

Takada enters five minutes in accompanied by bassist Kunishi and Suematsu.

The vamp expands and the force increases in density until there's nowhere left to go but silence.

Quiet sounds and echoes emerge from the emptiness, gradually introducing guitars and drums.

The band purposefully erects a wall of overdriven shoegaze -- inspired, all but unhinged noise that eventually destroys itself in a howling wall of metal aggression.

"Ely’s Heartbeat" commences as a lullaby with six circular cascading notes.

Processional drumming enters and the harmonic center grows.

Gorgeous guitar tonalities engage chamber strings and piano.

Closer "The Last Scene," with its piano and guitar interplay, is, in its intro, nearly a blues.

Drums accentuate that notion, but before long, additional guitars carve out a new foundation and blurred strings frame it all as a compressed lyric center that heightens the emotional impact before peeling away and whispering to a close.

Requiem for Hell doesn't offer anything "new," and it doesn't try to.

This album brings together the various musical notions and conflicting emotions expressed in Mono's music from previous outings and delivers them as a complex but unified whole.

It's intimate and powerful and, at 48 minutes, it's also a perfect length.

Requiem for Hell is simultaneously a perfect introduction to and summation of Mono as a band.