On respective edges of America - Oregon and Maine - Keith Kenniff records quiet music at night. "When things are calmer," he says.

"My mind is less distracted when I know that everything is dark outside." For over a decade, such has been the mode - nocturnal, unrushed, using the same mini-cassette recorder, "a lovely little imperfect way to treat sounds" - for one of the country's most understated composers.

Kenniff has housed dozens of ambient releases under the name Helios since 2004, alongside post-classical output as Goldmund, shoegaze pop with his wife Hollie as Mint Julep, and commissions for film and television.

It is a reliably transportive body of work that's earned Kenniff a cult following, and a genuine modesty that's kept him on the fringes, right where he prefers, in the dark.

Veriditas, the sixth Helios full-length, introduces unusual shapes and landscapes to the Helios catalog.

Whereas past songs have followed traditional structures - discernable b ell curves with beginnings, arcs, and ends - the focus here is texture and harmony.

"I wanted to explore emotionality within something more static." Synth-tones radiate and hum as vignettes, often crisp and cloudless, other times smeared to a queasy Boards of Canada-like unease.