Hainbach and Ah! Kosmos release Gentle Hum, made with lab gear

Gentle Hum found Hainbach and Ah! Kosmos expanding a collaboration that began with their 2023 debut Blast of Sirens. The new 14-track album, released April 24, 2026, leaned into the kind of unruly sound sources that have made Hainbach a cult figure far beyond experimental music circles, from telephone line testing equipment to hardware salvaged from nuclear testing facilities.

Hainbach, the professional name of Stefan Paul Goetsch, has built that reputation through a steady stream of work that sits between composition, performance, and education. His official site describes him as a Berlin-based, award-winning film composer, and says his ensemble pieces have been featured at Witten, Gaudeamus, and Impulsfestival Halle. His YouTube channel, launched in 2011, is devoted to experimental electronic music and odd instruments new and old, and it has become a major part of how he reaches listeners who might never encounter this music in a concert hall.

That platform has also turned unusual machinery into shared reference points for a wider audience. One of Hainbach’s better-known videos, The Surprising Musicality of a Telephone Line Simulator, helped turn a vintage line-testing device into a piece of internet lore. AudioThing later used that same instrument as the basis for Lines, a feedback multieffect and synthesizer modeled on the Axel Telephone Line Simulator, a direct example of how Hainbach’s niche obsessions have begun to shape tools for other musicians.

The appeal is not only technical. In a recent interview, Hainbach said he played The Legend of Zelda: Breath of the Wild with his children during the pandemic and found it to be a meaningful shared experience. He also said his favorite everyday tool is still a Swiss Army Knife, while showing little patience for substitutes such as credit-card-sized multitools. Those details fit the same persona that has made him a prolific presence online, with six albums released in 2025 alone, plus a handful of singles and EPs.

Ah! Kosmos, the project of Turkish composer Başak Günak, gives Gentle Hum a second point of view, and the pairing underscores a larger shift in experimental music. A creator once associated mainly with lab benches, test rigs, and obscure electronics now operates inside a platform ecosystem where YouTube, Bandcamp, and streaming listings help transform specialized technique into durable artistic identity. Gentle Hum is not just another collaboration; it is evidence that the boundary between experimentation, instruction, and fandom has become porous enough to sustain a serious audience.