Composer Anna Thorvaldsdottir has released two albums in the last 12 months, both of great potential interest to fans of adventurous music, whether they start from a classical, metal, or even electronic background. Aerial, which appeared in November 2014, gathers six compositions for groups of various sizes, from duos to full orchestra (get it from Amazon). And in August, Thorvaldsdottir released In the Light of Air, on which two of her compositions—the lengthy, four-part title suite, and “Transitions”—are performed by ICE (the International Contemporary Ensemble). (Get it from Amazon.)

Thorvaldsdottir’s compositions combine abstraction, a keen use of space and the sonic field, drones, ritualistic percussion, and surprisingly lush melodies. The six tracks that make up Aerial seem to arise almost imperceptibly out of silence, like figures emerging from mist; and though they were recorded under varying circumstances, with radically different ensembles, years apart, they work together to become a cohesive album-length statement. Percussion rattles ominously, as though signaling the beginning of a ceremony we don’t understand; horns and strings and sometimes synthesizers issue long, droning tones that harmonize in a barbed way. “Into – Second Self,” the album opener, is a studio construction, allowing three musicians (percussionist Frank Aarnink, horn player Stefán Jón Bernharðsson, and trombonist Sigurður Þorbergsson) to overdub a total of seven horn and four percussion parts. The long horn lines flow across the subtly threatening percussion in ways that recall Sunn O)))‘s “Alice” or early ’80s Einstürzende Neubauten.

“Aeriality,” by contrast, is a live recording featuring the Iceland Symphony Orchestra. The strings gibber and surge, sometimes droning and other times offering soft, yet still unnerving strings of notes; a delicate piano periodically murmurs in the background; massive thwacking booms of upright bass erupt at unpredictable intervals, like someone slamming the door in the middle of the performance. Modern composition may not draw listeners to concert halls, but its techniques have been part of the scores to horror movies since the middle of the 20th Century, and “Aeriality,” with its disorienting drones, rumbling orchestra and sudden, high-pitched stings, would serve that purpose extremely well. Except that in its final third, it becomes lush and romantic, the strings swelling like a sunset on the horizon, and even the upright basses, which return, feel more like accents than disruptions.

“Trajectories” and the three-part “Tactility” are duos, for piano and electronics (the latter played by Thorvaldsdottir herself) and harp and percussion, respectively. Despite its nearly eight-minute running time and three-part structure, “Tactility” passes quickly, and sounds almost improvised. Each thump of percussion, or ping of a single harp string, seems like a call into the darkness, most of which go unanswered.

Stream Aerial on Spotify:

In the Light of Air is a very different album; it contains only two compositions, the 32-minute, four-part title piece and the nearly 11-minute “Transitions,” and it’s all performed by one group, the ICE. (“Transitions” is a solo cello piece, commissioned and performed by Michael Nicholas.) “In the Light of Air” was commissioned by the group, and created with input from the musicians who’d ultimately be performing it; Thorvaldsdottir discusses this in an interview on the ICE website. She says, “The process of writing the music for In the Light of Air was actually not different from writing other pieces. It was great, however, to be able to meet with the specific performers during the writing of the piece, and I really wanted to get to know each of them well so I could write specifically for them; this was really very precious.”

The resulting music has a much wider emotional palette than that heard on Aerial. It’s lighter and more flowing, with a tenderness and romanticism almost entirely absent on the earlier album, as though an affection had built up between Thorvaldsdottir and the musicians, which then seeped into both the composition and its performance. Though the metal percussion and deep, resonant drones remain, the feeling is less like attending a midnight ritual that might end in the sacrifice of one’s own life, and more like a gathering to welcome the morning sun on the summer solstice.

Thorvaldsdottir’s music is likely not what the average person thinks of when they hear the phrase “classical music.” However, its atmosphere and tonalities are likely to appeal quite strongly to fans of forbidding music of any genre (dark ambient, industrial, noise, post-metal). With a quality sound system and proper lighting design, the music on Aerial could turn a concert hall into a deeply unsettling place, one filled with listeners under 60. On the other hand, In the Light of Air, while it retains the emotional intensity of the shorter pieces, adds enough brightness and positivity to demonstrate the vastness of Thorvaldsdottir’s compositional imagination and sonic universe.

—Phil Freeman

Watch the video for “Luminance,” from In the Light of Air: