Instrumental post-metal lost its novelty value in these circles a long time ago. Done well, though, and it still has a lot to offer, as Mondrian Oak prove. Aeon is an atmospheric album, which has been put together with craft and subtlety. It is sometimes sinister, with its clanking, fuzzy bass lines, and at other times uplifting. And it is a mercifully restrained piece of work, eschewing the more predictable “start soft and build slowly up to an epic climax” approach, for some much more enigmatic compositions with a free-flowing, unhurried feel.

One of the things I like about Aeon is the way it drifts back to signature ideas across the album’s hour-long running time. Most obviously, 1 begins the record with the elegant simplicity of two notes, an octave apart, plucked as a meditative, hollow drone. Snatches of melody (which sound a bit like the theme from the recent BBC show Sherlock, British readers) hover overhead, draped in ambient hum. At the climax of the record, 7 (tracks are numbered), layers of swirling harmony are stripped away to reveal the same two notes; an simple but eloquent way to draw the album full circle. It sounds like a small thing, but it’s nice to hear bands thinking about continuity like this.

That thoughtfulness spills over into the intervening 45 minutes, also. Much of this is the kind of music that demands total silence and a darkened room. Both 4 and 7, for example, channel latter-day Earth in their muted, muffled washes of reverb-drenched sound. The former, in particular, allows a darker, scuzzier tone in the bass guitar to crackle to the surface without ever being given power over its gentler six-stringed counterpart. Generally, this is the band’s dynamic: the bass is harsher, giving Aeon a sense of lurking but controlled heaviness as with the thudding 2, whereas the guitar seeks to squeeze out intriguing harmonies. But there are occasional flourishes in the instrumentation, which also add a great deal. The delicate acoustic tones overlaid on 3, or the weird, prog-rock whistling sound that takes a surreal lead in 7.

Similarities could also be drawn to bands such as Pelican, in the record's heavier moments. While Aeon never becomes 'metal', as such, it does have an underlying darkness which occasionally manifests itself more strongly. Tracks like 5 are constructed around glowering, sludgy riffing, but this is always balanced by sudden fallaways into near-silence, as on the 1:40 mark. 6, in particular, is an imposing piece of music, with its thudding percussive beat constituting the centrepiece to a primal first four minutes. Overall, Aeon is a rather impressive release, deserving of wider attention.