The atmosphere surrounding the earth is made up of five distinct layers. Heading skyward, we start with the troposphere, which is the atmosphere we live and breathe in. Beyond that is the stratosphere, followed by the mesosphere, the thermosphere, and the exosphere. Lacking any concrete boundary, each layer is distinguished from the one preceding it by a decreasing difference in temperature brought on by an increase in height.

Scandinavian musician/composer/sound artist Marja Ahti was commissioned by the French audio/visual institute Ina GRM to create something based on the idea of travelling through those layers. “The Altitudes,” the opening track of her latest album, The Current Inside, put out by the Hallow Ground label from Switzerland, feels surprisingly earthbound – yet all the more compelling for it.

Rather than offering conceptual program music that becomes more barren, abstract, and blood-freezingly crystalline as it progresses, Ahti instead conjures up a kind of breathing sonic organism that seems to grow and transform itself with each aspiration. The twenty-minute piece develops in a series of measured, layered, swelling tones that build out of silence and recede back into it. What surprised me at first listen and delighted me in equal measure was the early inclusion of field recordings containing squawking geese, chittering sparrows, and the drip of rain from a ledge landing in what sounds like a shallow, pebbled rut. Ahti gradually moves away from those effects but their earthy, recognizable presence remains in spirit, keeping what comes after it rooted in things material and concrete.

Not to suggest that all is even-keeled tranquility. “The Altitudes” glowers and hovers and throbs, with sounds staticky, mournful, accusing, crackling, or discomfitingly whispery and hair-raising, all of them cycling and mutating with each new iteration. Ahti’s continual stops and starts build and maintain a tremendous and satisfying tension so that when the end is eventually reached, one is left with a feeling not so much of being finished as of being released from the grip of something. You have been moved while listening but through a space with no fixed dimensions. It’s a powerful piece of work.

The four shorter pieces that make up the rest of the album almost function as a suite. The titles – “The Currents,” “Lost Lake,” “Fluctuating Streams,” and “Sundial” – might suggest a thematic portrait, but nothing so straightforward is presented. What holds them together is Ahti’s command of her materials and her ability to create and shape the space in which they exist.

“The Currents” is spooky and spectral, a brief but creepy slice of the sounds one might hear from a night spent in a haunted house. In “Lost Lake,” an uneasy blend of metallic strikes, glowing bell tones, the crackling sounds of footsteps on leaves and twigs, and the odd plink or splash of water evokes emotion without shaping or manipulating it. “Fluctuating Streams,” the highlight of the group, is composed of layers of long tones and overtones, tentative wordless vocals and deep, magnetic rests that swallow up all the sounds that precede them. It has the pace and cadence of ritual and ceremony but without the suggestion of anything remotely spiritual. The final track, “Sundial,” is filled with the sounds of camping: the hushed roar of a campfire, the cry of seagulls, the distant laughter and screams of children playing. But a persistent presence of ominous, layered tones insinuates itself into the speculative scenario, functioning as a reminder of an underlying unease or limit that can’t be transcended.

One comes away from listening to The Current Inside with a recharged awareness of space. The spaces Ahti creates and explores in her work are intimate, segmented, elongated, vacuous, distended with pressure. They evoke uncertain emotions and forestall any opportunity to name or resolve them. With repeated listens, they reward with the continued revelation of hidden textures and new ideas.

Concurrent with the release of The Current Inside, but independent of it, is Portals, a single, twenty-two minute track featuring Ahti in collaboration with cellist Judith Hamann, released by Café Oto. Overcoming relative isolation while stuck in lockdown, the two artists traded tracks while composing Portals, relying on field recordings as well as cello, magnetic tape, and electronics. Aptly named, the piece takes listeners to all manner of locales, both actual and imaginary while never settling anywhere. Waves splash and land on a beach, a door opens somewhere, wood creaks, fat sizzles before mutating to static. An unidentifiable object is pounded and breaks into pieces. Nature and domesticity are witnessed and captured but no narrative is imposed. The disjointed, decontextualized material keeps one hooked and curious while Hamann’s sometimes sonorous, sometimes piercing, sometimes beseeching cello adds warmth, color, and emotion. Deep with intrigue and mystery, Portals is a keen response to the deprivations of lockdown and a crafty antidote to it.