Ever since it began in 2017 the remarkable Belgian label Aspen Edities has revealed a strong attraction toward fragile, if not translucent sounds. Launched by Antwerp guitarist Ruben Machtelinckx, euphonium player Niels Van Heertum and writer Sanne Huysmans, the imprint has developed an exquisite improvisation-based aesthetic marked by small, patient sounds, elegant gestures, and stately melodic fragments, perpetually attractive but somehow elusive. While the label primarily documents the thoughtful work of a tight-knit coterie of Belgian players, from the start it has also forged connections with a variety of Norwegian improvisers, including trumpeter Arve Henriksen, hardanger fiddler Nils Økland, and percussionist Ingar Zach, who himself has long been a driving force of the Sofa label.

As a matter of fact, Zach has appeared on two Aspen Edities releases, both collaborative efforts with Linus - the duo of Machtelinckx and reedist Thomas Jillings. Now Zach is back with a stunning solo recording for the label, “Strumento di Etimo Incerto”, which marks a new zenith in his work on the Gran Cassa, the gigantic symphonic bass drum which he has masterfully subverted into an elastic platform for deep sonic exploration. Zach is a veteran sound experimentalist, who has found disparate ways to situate his coloristic machinations. He’s a founding member of the groove-oriented, texture-rich trio Huntsville and he also plays in the remarkable improv quartet Dans les arbres alongside keyboardist Christian Wallumrød, clarinetist Xavier Charles, and guitarist Ivar Grydeland. Zach is also a seasoned improviser who’s worked with the likes of Derek Bailey, Mazen Kerbaj, Jaap Blonk, Agustí Fernandez, and Rhodri Davies, among others, to say nothing of a composer whose work have been interpreted by Speak Percussion, Quatuor Bozzini, Ensemble MusikFabrik, and Alessandra Rombolà.

Still, no single practice conveys his musical aesthetic like his rigorous solo practice, and “Strumento di Etimo Incerto”, his eighth such recording, achieves a new creative apex. The album’s A-side is occupied by “Cicchitaredu”, a shape-shifting marvel that dissolves any perceived boundaries between insistent rhythm and abstract sound. Zach turns the Gran Cassa on its side, transforming the huge drum into a veritable sound table on which he lays his various tools. The new album prominently features the use of small vibrating speakers, which provoke additional resonances, turning the drum skin into a virtual organism shadowing, amplifying, and transforming various frictions, thumps, and pulsations.

Over the course of 22 thrilling minutes Zach weaves an endless array of new details into an insistent machine-like pulse, dangling between some kind of alien techno music and a percussion quartet heard underwater. The percussionist triggers a wide variety of looping and repeating rhythmic phrases that come and go along the way. There are pregnant pauses - a brief second for inhalation - before the sounds resume, in altered fashion. Terse, cycling string-like patterns, simple grooves meted out with brushes, floating ambient washes, wordless vocals, and recurring subsonic moans chug along with the relentless energy of vintage Neu!, but on top of the groove Zach is perpetually adding and subtracting fleeting details, using the fixed elements as a blank canvas for live action painting with sound.

Zach generally eschews the obvious patterns on the six-movement “Le finestre I-IV”, an assortment of terse studies using skin resonances. There are sections where Zach “plays” the drums, with compact little rhythmic patterns piercing a hushed electronic din, separating some of the concepts and methods used on the flipside into discrete episodes, but they easily stand on their own, while other sections arrive as self-contained mini-compositions of kinesis and abrasion. The closing work, “Davoli”, almost seems like a minimalist response to the maximal energy and motion of “Cicchitaredu” emerging slowly from silence to open a hushed, tenderly sustained ambient glow marbled with tonal swirls until a quiet jangle of bells embroiders the meditative calm.

Issued in a numbered edition of 300 copies on vinyl and CD, the album features art by Ives Maes which surrounds the album with two images distinguished by wood grain, a lovely metaphor for the microscopic patterns that lay at the heart of Zach’s music.