Everything they’ve said is true.

“The introvert[ed] and darker sibling, who lives in the attic.” “More introspective and freeform than its poppier partner.” “Brimfull with dark secrets and distorted memories.”

All of these are the descriptions being tossed out by Röyksopp‘s camp in advance of the release of their fourth studio effort, Senior. And for once, a band’s press releases are entirely hyperbole free.

In stark contrast to the album’s companion piece–Junior, one of 2009′s greatest releases–Senior is entirely instrumental, brooding, for the most part, quite moody.

The noises used to build the album are dusty, weathered and strange; not unlike what you’d find rummaging through the boxes buried deep in some hidden nook at home. Each song creaks and crinkles with a vintage feel that’s both organic and supernatural, lending itself to that same magical energy behind each of Röyksopp’s productions.

On “Senior Living,” steel guitars mash together breathlessly with an angelic choir, sad strings, and twinkling electronica. “The Drug” blends muted ’90′s house synths with a trip-hop beat and occasionally jarring electro-interferences. “Coming Home” sees the world floating away on a dreamy, lush soundscape far into outer space–all set to the beat of a ceaseless metronome.

Truthfully though, it’s a bit pointless to point out “highlights” from the album. As the duo have stressed in the very slow promotion for this album’s release, this is an instrumental album, meant to be consumed all in one go.

It’s not a collection of stompers and ballads, and it’s probably the group’s least commercially appetizing offering thus far. That, however, does not take away from the album’s production value, which is nothing less than superb.

Fans will be pleased to know that the signature Röyksopp sound–the melancholy melodies and cyclical rhythms that have come to color each one of the duo’s releases ever since Melody A.M.–is still alive and well here, albeit buried under all the strange miscellanea.

Take for instance “Tricky Part Two,” which uses the instrumental from their 2009 album track “Tricky Tricky” (featuring Karin Dreijer) and morphs it into an even more complicated composition, incorporating elements of dance and electro-pop by the song’s end.

Even some of the band’s signature sounds from their debut make appearances here, as the light electronica flares from songs like “So Easy,” “Eple” and “Sparks” make brief cameos in tracks like “Forsaken Cowboy.”

While the Nordic duo have always had a knack for delivering songs with killer stories (“The Girl and The Robot,” “What Else Is There?”), they’ve managed to go a step further with Senior by proving that they can still supply narratives simply through music: “The Alcoholic” certainly seems to tell the tell of its namesake as a demented, drunken synthesizer waves and warbles its way through the countryside. No really, you can visualize it. Just listen to those birds chirping! And the rain!

In the end, Senior only aids in proving Röyksopp to be one of the innovative musical acts on the scene. They can churn out crunchy, sophisticated pop confections (“Only This Moment”), but they can just as easily evoke emotion through sound and sound alone.

For all info on the upcoming release of Senior, click here.