Amorphous, open-ended, unstructured time, with undercurrents of foreboding, pockets of boredom and fleeting interludes of peace or reassessment. That’s what Covid-19 has brought to many people — and it’s a mental state that Brian Eno’s vast recorded catalog has been prepared for since he first popularized the term “ambient music” in the 1970s. The long days and featureless nights of self-quarantine offer an opportune moment to revisit — or get acquainted with — Eno’s time-warping music.

He does have other skills. On four solo albums from the 1970s, after he left Roxy Music, Eno thoroughly mastered rock-song structure, with slyly cerebral lyrics and skewed instrumental sounds; all four albums are gems, particularly “Before and After Science” from 1977. He has intermittently made song albums in the decades since. And his 1981 collaboration with David Byrne on “My Life in the Bush of Ghosts” — shaping found-sound sampled vocals from international sources into rhythm-driven, club-ready tracks — opened new doors in dance music.

But for the most part, Eno has channeled his pop impulses into production and collaborations — with U2, David Bowie, Talking Heads, John Cale and lately Karl Hyde of Underworld. Yet the bulk of his own recordings, and all of those selected here, are instrumentals that, old or new, are particularly suited to orchestrate this uneasy historical moment.

Eno was not the first to make music designed to maintain a subliminal, atmospheric presence while evading the foreground. By his account, medical circumstance led him to thinking about music as just one element in a larger environment. When he was immobilized after an automobile accident, a friend left music playing on a record player he couldn’t reach, at such low volume that it melded with all the other sounds in the room; Eno being Eno, he ended up listening with John Cage-like attentiveness. That gave him the idea for his quiet, ambient (although he hadn’t yet settled on the term) 1975 album, “Discreet Music.” Soon, Eno would stake out an ambient music genre that has since been populated by countless composers alongside him.