In 2013, The National played their song Sorrow for six hours non-stop at New York’s MoMA PS1 – part of a project with the Icelandic performance artist Ragnar Kjartansson.

Kjartansson filmed the whole thing, titling it A Lot of Sorrow. This video is now playing at Berlin’s König Galerie. And yes, it is also six hours long.

I’m not sure how long I’ve been sitting and watching The National perform their three-minute-and-twenty-five-second song for, but it feels like forever. I am in a cavernous dark room, on a hard bench, my back starting to hurt from leaning forward towards the screen. The only light in the large grey space comes from the vast video projection in front of me. Maybe it’s just the huge emptiness of the König Galerie, but as soon as I walk in I feel like I’m in some kind of holy place: somewhere slightly outside of space and time, like one of those temples on top of mountains that you have to hike for days to reach.

On first hearing about this show, I wondered: How is it not going to be really, really boring? For fans of The National, I could sort of get the appeal – but I’d never heard Sorrow before, and couldn’t name even one of the band’s albums. Boring though it might be, I figured that at least this marathon-length video would offer a solid introduction to their sound.

It was late afternoon when I visited the König Galerie, and on the screen, it was obvious the band had already been playing for several hours. Empty food containers littered the stage. Everyone had their dress shirts unbuttoned at the collar and sweat beaded on their foreheads. Even the crowd looked worn out. It was nearly impossible to understand the lyrics at first, lead singer Matt Berninger murmuring into the microphone. Every time the band finished the song, the crowd clapped and cheered as if they hadn’t already heard it at least 50 times already.

Sorrow began again, and again, and again. I began to understand the words: “I don’t wanna get over you. I don’t wanna get over you…” The rhythm of the repetition became hypnotic, the song gradually familiar, as if I’d been listening to it for years, instead of part of an afternoon. I started feeling as if Sorrow had soundtracked every important moment in my life. As if Sorrow was playing in the background when I was born. Sorrow had been playing, on repeat, since long before I came into the world, and Sorrow would continue after I left it. I was sliding into the kind of trance reserved for those moments when, on a bus ride, or lying in bed, you put a favourite song on repeat and begin to fall asleep. The song is so familiar that it loses meaning, becomes just another part of your thoughts. But just that morning, Sorrow had meant nothing to me.

The König Galerie has only recently relocated to St. Agnes, an intimidating 1960s-era concrete church-turned-art space. It’s hard to imagine a better location for this show. A Lot of Sorrow is a film that rewards an intense level of focus, the sort which can only be achieved properly in meditative darkness. It reminds me of the “om” meditation mantra: a familiar frequency which – repeated often enough – lets you segue from one dimension to the next.

As The National play, Sorrow warps and shifts, slows unbearably, speeds up again, remains somehow the same. The crowd, unbelievably, keeps dancing. It’s an incredible testament to this band’s talent that they are able to keep going, still in tune, in tempo, powerful, after playing the same song for what literally feels like a lifetime. After a few repetitions, A Lot of Sorrow inevitably suggests the possibility of Sorrow being repeated forever. Time begins to fold back on itself: somewhere, at any given point in time, The National are playing the song Sorrow, and when they finish it, they will wipe the sweat from their foreheads and begin playing again.

I started to believe I could hide within the repetitions of the music, and it would never end, and time would not keep accelerating. This must be the feeling Kjartansson is looking to achieve. More than anything, more than a tribute to a band or a test of musical endurance, A Lot of Sorrow is an effort to stop time. And as much as stopping time is possible, at least inside the MoMA PS1 or the König Galerie, Kjartansson has succeeded. He’s taken a tiny, three-minute-and-twenty-five second slice of time, and stretched it across forever.

A Lot of Sorrow runs at König Galerie, Berlin until August 23