As he gets older, Brian Eno is discovering that all roads lead back to his 1975 ambient milestone Discreet Music, and with good reason: Eno conceived the piece in a hospital bed while recovering from a car accident, so, in a sense, it’s forever linked to a quiet, unhurried pondering of his own mortality. This practice of composing music as a response to the fragile gift of life—and by association, to the gently swirling eddies of thought and memory, which contemplation of that gift inspires—has become an intuitive exercise for Eno, to the point that Reflection, his latest in a literally accidental and long-running series of ambient sound recordings, comes across as a pure distillation of “generative music.” The term has multiple layers of meaning, but at its simplest, it connotes music that unfolds differently with each new playback. Synth-based and spare, at a continuous 54 minutes in length, Reflection can blend into the aural background just as easily as it rewards close and focused listening. And, if the subtly shifting sonic environments somehow aren’t enough, then Eno has released a deluxe version in the form of an app, making the possibilities truly endless.