Sleep Theory’s UK debut has been upgraded twice. Since the release of their Afterglow album last summer, frontman Cullen Moore has found himself the face of rock’s fastest-rising band. He’s ready for it, locked in…
Cullen Moore is, ironically, something of a night owl. On any given day, the Sleep Theory frontman – disarmingly amiable, even on just a handful of hours’ rest, with an icy-white Cheshire Cat grin stretched across a face that hides beneath a baseball cap adorned with the words ‘Be a good person’ – has “to physically exhaust myself” in order to drop off.
“Even when we’re on tour, I’m the last one to bed,” he says. “And I mean 5am, 6am. I’ll be watching the sunrise. I’ll get on YouTube and see some clip about Jurassic Park or something, and I’ll spiral.”
And yet evidence suggests that good things happen for Cullen and Sleep Theory in the dead of the Memphis, Tennessee night. Take, for instance, the release of their first single, the 20-odd-million streaming viral sensation Another Way, in January 2023.
“I was laying on my bed one night, and it was real late,” Cullen recalls. “I was feeling pretty good – we’d just done some band photos that day – so on an absolute whim, I threw up a teaser and a video with the song. Eventually I fall asleep, and when I wake up I had almost completely forgot about it. When I checked back on it, it was doing its thing,” he smiles.
Or, for a more recent case in point, look at their forthcoming debut UK tour, which, slated for this February, sold out its initial scheduling in the matter of 30 minutes after going onsale while Cullen snored on the other side of the world. Waking up to the news, the decision was taken to upgrade the venues. Another sleep, another sell-out. A third upgrade means that when Cullen, Daniel Pruitt (guitar), Paolo Vergara (bass) and Ben Pruitt (drums) step out onstage in London they will do so at a venue four times bigger than they had originally planned.
Such has been the unstoppable ascent of one of 2025’s biggest success stories. Theirs is not, however, an overnight explosion – figuratively or literally. Rather, the rise of Sleep Theory has been one of dedication, patience and slow-burn perseverance, since their inception way back in 2018.
Then, Cullen was a multi-time college drop-out turned U.S. military veteran “without a plan B – it was music or nothing for me. I’m not even saying that to make myself feel better. I dropped out of college so many freaking times, and I was only going there at all because my parents wanted me to, and I didn’t want to disappoint them. And I didn’t want to end up living under a bridge.”
Now, far from it, he’s being spoken of as a contender for rock’s Next Great Frontman.
Still, the achievements of the past 12 months, which Cullen joins Kerrang! to dissect from his home garage where he’s enjoying some rare downtime, are numerous and impressive. Handpicked support slots with Beartooth, Falling In Reverse and Papa Roach. An extensive headline tour, spanning the length and breadth of the U.S. and packing out rooms wherever it called, be it Oklahoma or Seattle. The release of debut album Afterglow, on the esteemed Epitaph Records; “the sound of adolescent dreams come to life” closed our rave review, which arrived in the same week as the band’s debut K! cover.
Following appearances at Louder Than Life, Inkcarceration and Aftershock festivals, Sleep Theory’s first trip over the pond this year has been swiftly followed by their booking for Download 2026 in the summer.
It’s enough to make even the most seasoned of heads spin. But not Cullen. And no-one who has spent more than five minutes in the company of a man from whom a nonchalant confidence emanates would be surprised at that.
“Confidence and arrogance are close cousins,” he reasons, “but I have always had complete confidence in myself and this band. It’s a mental thing for me. I know I am capable of doing anything I put my mind to. If I wanted to be good at, say, snowboarding, I would obsess over it until I was. Too many people pitty-patty around being ‘interested’ in something.
“I don’t let my mind get clouded by worrying about what might happen,” he declares. “I have no time for ‘what if’.”
Our man is not, in fact, good at snowboarding. “I would be if I wanted to be, I promise you!” he howls. “I’d be out on them slopes and I’d be [Olympic gold medal ’boarder] Shaun White, boy, I’m telling you!”
If Cullen insists that he always thought his future would hold the level of success that 2025 has brought – “Did I believe that we would ever go on tour with a big band? Yeah. Did I ever believe that we would have a successful headline tour? Yeah…” – a rare chink in his steel-plated facade arrives when he admits to a modicum of surprise at the speed with which Sleep Theory are growing, especially in relation to the band’s upcoming UK tour.
“I knew that we would get to the UK,” he nods. “And I knew we’d have a chance of selling out some shows. But this fast? That’s pretty insane to me.”
A further hesitation arrives when asked to attempt to qualify quite why this is all happening to him, and his band, right now.
“I would like to think it’s the music,” he shrugs. “Do I think the music is great? Yeah, I think it’s pretty cool. But I’m a perfectionist. And I did not think people would love it enough, if I’m completely honest with you.”
Instead, Cullen attributes a large part of Sleep Theory’s rise to that of their relatability. Afterglow is an album of accessibility on multiple levels, from the R&B pop sheen that acts as a palate-cleansing, mainstream-baiting counterpoint to its riffs and breakdowns, through to the record’s themes of trauma and recovery. When Cullen sings, ‘When it takes everything to survive / It’s hard enough just to feel alive,’ on smash-hit lead single Numb, they are words he knows, that speak to the heart of those in the crowd every night.
“I feel like people have been starving,” he says. “What they really want is something to connect with. Trends in music come and go; how do we write something that creates a bond with someone?”
His connection with their ever-swelling audience – his role as the leader of Sleep Theory – and what that all means is something that Cullen continues to come to terms with, “understanding the influence I have”. He breaks down his fellow peers into three tiers: ‘frontman’, ‘celebrity’ and ‘icon’. He remains firmly entrenched in the former category, he nods, but he’s learning what it might take to reach his desired top-tier. An even great lever of dedication, for one.
“I love seeing people happy, and being the reason that they’re smiling, so I do love touring – but I know I’m tired from [2025], and I’ve missed home,” he says.
Respect is another. “People are looking to me as an example now. The biggest thing that people can lose is not their achievements, but people’s respect.”
It’s in such terms that he views Sleep Theory’s rise – not from a position of pressure that’s come about now that he has something to lose, but added responsibility.
“The most important thing is to stay grounded, and stay true to yourself,” he nods. “I don’t see our success as now giving me something to lose, because I always had something to lose. Success is painted by the individual, and I would say my life has been a success whether or not I have music. My family, my people around me, my environment – that’s success.”
Key to that remains blocking out the noise. It’s served the band well so far, after all. Having previously described his role as like that of a movie director, Sleep Theory’s is a vision meticulously plotted and constructed, transposed from Cullen’s mind to reality. Theirs is a sound as accessible as it is divisive, its glossy sheen like manna from Heaven to many, and like nails on a chalkboard to others, yet their commitment to their approach is equally unwavering in the face of adulation and contempt. (At least they quickly shook off the early laughable accusations of being an “industry plant”, whatever on earth that means.)
But with growth comes attention, and with attention comes opinions, and with opinions comes bad actors with their own designs for milking Sleep Theory’s success.
“There’s going to be plenty of people that want to see this or that from us, and have their own motivations for doing so,” Cullen shrugs. “You just have to stay focused and shut those things out. If you let demons in, they’ll dance.”
He points to the advice imparted on him by Ronnie Radke during Sleep Theory’s time on the road with Falling In Reverse: “‘Don’t let anybody try to discourage you. Don’t let anybody get in the way of your thinking. Keep on doing you.’”
Asked, then, where another year of ‘doing you’ will lead Sleep Theory in 2026, Cullen is for the first time at a loss for words. If, we posit, we were to conduct this same interview exactly 12 months from now, what does success look like then?
“The fact that I’m still gonna be the same way in a year’s time,” comes the eventual reply. “To be honest with you, I just don’t know. Book the interview now and ask me then. I’m not someone who is good at looking back or forwards. I can barely tell you about my day yesterday, and I definitely can’t tell you about my day tomorrow. Live in the past and you’ll dwell there; worry about the future and you’ll start to stress about the places you think you should be, and the things you’ve said you’ll do, and if you don’t get there, you’ll feel you’ve failed. I just live in the moment, and if you do that, you’ll always feel like you’re succeeding.”
And it might just help Cullen get some sleep, too.
Afterglow is out now via Epitaph. Sleep Theory tour the UK from February 6. This interview originally appeared in the winter 2025 issue of Kerrang!.
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