There comes a time during even the most enjoyable of live shows when temptation strikes, and you quite fancy a nap. It doesn’t have to be an overwhelming urge — just a slight, half-second realisation that home is quite far away. Even when a multi-million selling global sensation is performing backflips on a trampoline at the O2; or when a fast-rising new band stampedes through the hype with an unforgettable local gig; or when a famous recluse comes out of retirement to play a oneoff show in a church — yes, these things are great, but so is bed.

So what if there existed a show where you didn’t just have the option to take a kip, it was actively encouraged? West German-born, British contemporary composer Max Richter has just the ticket. In 2015, Richter released Sleep, which he describes as an “eight-hour long personal lullaby for a frenetic world”. All of Richter’s works take on a journey of their own, but this one is specifically designed to aid the process of sleep, or at least provide a long-lasting escape route from an increasingly hectic existence. It begins as a soothing lull of looped pianos, progresses into a surreal, five-hour web of comforting instrumentation and choral waves, before upping the urgency just before it’s time to wake up. After writing the piece, he consulted neuroscientist David Eagleman to check that his creation’s low frequencies corroborated with studies on the ideal sleep process, and it did.

Before tonight’s Barbican sleepover at London’s Old Billingsgate, Sleep has only been performed in its entirety six times — understandable, given the logistics and commitment required to flesh this out into a living, breathing, eighthour-long nightcap. While those in attendance doze off, having paid £75 to £125 for the night, Richter and his ensemble — three violinists, two cellists, one soprano and one sound engineer — are required to pull an all-nighter.

It’s not hard to spot the venue from a distance, due to a queue of humansized pillows, duvets and giant throws. But once inside, I realise I’ve come remarkably unprepared. Each ticket includes one complimentary bed and mattress, which is all well and good. An hour before Richter turns up, most punters — including one Jarvis Cocker — have already gotten changed into matching pyjama sets, lined their mattresses with sheets, and neatly arranged blankets over duvets like they’re staying for the week. Meanwhile, I’ve turned up with a single hand-sized pillow and a seemingly snug blanket that, once laid down, won’t reach over my feet. For some reason that I can’t explain in hindsight, I’m also wearing a work shirt and the same skinny jeans I’d sport to Reading Festival. I’m somewhere between an indie kid and a city boy intern, while others around me look prepared for a monthlong meditation session, not a quick nap.

No sooner has it dawned on me that I’m as much prepared for a karaoke night as I am a prolonged sleep, Richter and his ensemble arrive on stage. The sound of passing traffic plays, Richter gives a quick speech about the purpose of Sleep — thanking his partner and the show’s executive producer Yulia Mahr — and he hits the first of several thousand notes on his piano. The performance will run from 11pm to 7am, no interruptions. Lined in rows, most attendees nestle their heads on their various castles of fluffy pillows.

Some start reading a book they’ve brought with them, or tuck into a complimentary muesli bar. Others stay upright, eyes fixed on the performance. Alcohol isn’t served, and mobile phones are prohibited. Starved of these trusty distractions, I decide to try and join the sleeping cast.

Within minutes, Richter’s playing begins to sound hypnotic. Sombre notes tread the same path, like they’re soundtracking the world’s longest funeral. He rarely breaks pattern. Every so often the lower register gives way to a wave of swelling bass, but he’s essentially creating a long, winding loop of soothing keys. It’s hard to say with certainty what happens next, because despite my outstandingly ill-considered bedwear and sheets, I’m out like a log. I seem to be blessed with an ability to sleep anywhere, in pretty much any situation — with the exception of flights, where I’m distracted by onboard entertainment and a recurring awareness of how a stray seagull nosediving into a jet engine could send the plane crashing down.

It isn’t a consistent, uninterrupted sleep. Soprano Grace Davidson has an unbelievable knack for hitting the same, skyhigh notes. To begin with, I assume Richter’s playing the same vocal sample out of his laptop, and it’s only when I look up — Davidson standing alone on stage — that I realise an actual human is behind this. At some point, however, those vocals become less comforting and more uneasy, as they’re accompanied by wall-shaking bass (without question, at one stage I can feel my entire jaw vibrating) that threatens to go off the, erm, Richter scale. Most punters are already in the midst of a deep sleep, consumed by said bass, burrowed deep in another dimension. But if you happen to be unfortunate enough to stir awake at this crux, it’s difficult to go back to dozing.

Eventually it happens. I dream weird dreams. One is the usual situation of being agonisingly close to missing the last train home, hurrying towards a station while knowing deep down that it’s about to speed off without me. This dream takes a twist, where Kendrick Lamar turns up and manages to stop time — more The Matrix than Bernard’s Watch — in order for me to catch the train. “Cheers K-Dot!” I say, and I’m welcomed onto the train by a pack of loveable dogs.

The second dream finds me, Inception-like, in this very room of Old Billingsgate. As with real life, we’re all laid in rows like olden-day hospital patients without the impending leg amputations. Only in the dream, someone behind me lets out a howl of, “We’re all just a big bunch of bast**ds, at the end of the day!” Who knows, maybe this actually happened. It’s easy to confuse reality with fiction, such is the constantly shifting, hallucinatory scope of Richter’s work.

There are few things stranger than waking up and immediately giving a standing ovation. Not least when you look around and see a hundred adults in pyjamas doing the same thing. I’d actually recommend starting every day with a standing ovation. It gets the blood flowing, and makes a standard, grey morning suddenly seem momentous. Richter and his knackered ensemble give several bows. Most in attendance are still waking up while clapping, so they seem unsure of when to stop. But there’s also something admirable not just in the persistence and staying power of Richter’s performance, but in how well it actually works. Sleep isn’t solely a sleeping aid. It’s an ever-evolving tonic for the alwayson and constantly occupied, an escape that gives you a new perspective on the day ahead. Despite all nearby Prets being closed at this ungodly hour, causing a mild panic, everyone leaving the venue looks like they’ve experienced something unique.

The Independent