Imagine you’re dreaming, and in your dream you pick a flower in heaven, and then you wake up with the flower in your hand. This is the kind of experience that composer Max Richter hopes to make palpable among the audience for Sleep, an eight-hour-long piece of music that explores of the liminal space between wakefulness and sleep, between consciousness and subconsciousness. Taking as its chronological guide an ambitious outdoor performance of the composition in central Los Angeles, this salubrious film immerses us in the making of the piece, and in the life of its composer. His wife, artist Yulia Mahr, is his mainstay in both his private and professional life. From her words, it’s clear that grand, intense art such as this cannot come into being without some sacrifice. The film makes palpable the sense of being present at the performance, partly through many visitors’ exquisitely well-formulated descriptions of their experiences. Shots of the audience lying on camping beds—some alone, others entwined with a loved one—flow organically into shots of the musicians, interviews and nocturnal city. And all this is accompanied by the enchanting music itself.