Sleep, by Max Richter, lasts eight hours. Richter has, in part, created it as, he says, an "eight hour pause" in our world of constant data - smart phones and 24-hour TV, Twitter, Facebook and Instagram. He appreciates the irony that Sleep, which is released by Deutsche Grammophon, in September, is adding to that data overload: because it is so long, it can only be released as an eight hour download, or as a stream. A one hour version will also be released, however.

Richter played me parts of Sleep at his studio in Berlin. Its main theme is a cycle of plangent piano chords, numbed and baffled by felt, that rise and fall like the slowly deepening breath of a sleeper. The chords are both soothing and melancholy. As I listened to them in Richter's Berlin studio, their depth and bass flooded the room. Later, the voice of a soprano, British singer Grace Davidson, sings a wordless lullaby over those same chords. Strings, with sonorous, long-bowed lines, also become part of Sleep's epic cycle.

The lullaby has a tinge of the Celtic, although Richter himself seemed surprised by that notion. The work will be premiered later this year in an old factory in Berlin, with the audience in beds and the performers working in shifts.

Richter says the work is also partially inspired by the Goldberg Variations, by Bach. The story (which Richter thinks may be dubious) goes that Bach created the work for Count Kaiserling of Saxony, who had trouble sleeping, so that he may listen to something during his troubled nights.

The recording process of Sleep was exhausting and demanding. The stately pace of the work putting huge demands on its performers, Richter himself and ACME, the American Contemporary Music Ensemble, with its precise notes and fragile, long tones. He says: "It’s actually proving quite difficult to work on - all the mastering engineers are moaning they are nodding off. And its a lot of work, it really is a monster. I went into it a little bit blasé... but it’s been tough."

•Sleep will be released on CD, vinyl, download, and streaming formats, all through Deutsche Grammophon, on 4 September. www.deutschegrammophon.com/en/artist/richter/