Sleep Theory are an overnight success that’s been decades in the making. Announcing themselves to the world with viral banger Another Way back in 2023, the Memphis lads have since enjoyed an explosive breakout story. But as Cullen Moore explains, the shapeshifting sound of debut LP Afterglow better represents an all-consuming slow burn that’s still just getting started…
Cullen Moore believes in being the best that he can be. It’s a hell of a high ceiling to reach for. Driving 400 miles from Memphis, Tennessee to drop his father with family in Lexington, Kentucky the night before we convene, memories were flickering in the back of the frontman’s mind. Music started as a shared dream with his dad – a talented R&B vocalist in his own right – and his first recollection is them singing Bobby Brown’s defiant anthem My Prerogative together on the family couch: ‘I don't need permission, make my own decisions / That's my prerogative.’
It's a mindset that would bear fruit in the boundary-breaking sound of Sleep Theory, a band whose smoothness and savagery has resonated unprecedentedly. Rock radio domination abounds and forthcoming massive festival slots have cemented breakout success. All with superb debut LP Afterglow still months away from release.
“We stopped at a gas station, a Buc-ee’s, and my dad asked me if I ever thought Sleep Theory was going to be this big,” Cullen relives yesterday’s conversation as today’s begins. “I was just like, ‘Yeah…’ I told him it was because I would never have allowed it to be any smaller. I’m so competitive with the things that I’m involved in that I refuse to let anything be less than I know it should be. I don’t know where that attitude comes from. It’s just the way I’ve always been. And it’s not about being ‘better’ than anyone else. It’s more about the drive of seeing someone do something and needing to find out how well I can do it for myself. Even if Sleep Theory hadn’t reached the level it has already, I’d just keep putting in the effort until it did.”
Unpacking his story with easygoing charm, there is nothing artificial about Cullen’s self-confidence.
Growing up surrounded by music just south of the Tennessee/Mississippi state line, a place he affectionately refers to as “Memphissippi”, has been a massive part of that. From Beale Street, home of the blues, to the gritty breeding grounds of Memphis rap, and the velvety opulence of Elvis’ Graceland, many of the defining sounds of the United States were born within half an hour’s drive of his family’s front porch.
Cullen has never even visited Graceland, however. Apparently many Memphians haven’t, in the same way that lots of people from Orlando have never been to Disney World. He’s never seen the legendary marching ducks at the city’s Peabody Hotel, either. And he’s only recently checked out the city’s Pyramid: a colossal Bass Pro Shop complete with shooting and archery ranges as well as an alligator-infested in-store swamp. Instead, music got its teeth into him courtesy of a familial chorus of voices even closer to home.
“People ask when I figured out that I could sing,” Cullen continues. “I honestly don’t remember – I just sing. It’s something I’ve always been able to do. My dad was always singing. My grandma, too. My uncle. My other uncle. My aunt. My great-aunt. We’re all singers. And we all do it naturally. Because of that, my introductory experiences with so many different things in life have involved music. It’s such a core piece of who I am. There was never any doubt it was what I needed to do.”
“I refuse to let anything be less than I know it should be”
Seeing his father in the grainy VHS of a music video made with his mother solidified the idea that music as a career could actually be attainable. Both parents had worked hard to give Cullen a good upbringing and the opportunities he deserved. And although they encouraged their young son to keep his head down at school and make music a ‘Plan B’, that was never really going to be his path.
“I’ve been ‘doing’ music since I was 12,” he shrugs. “I’ve been in the studio since I was 14.”
A lot of things still needed figuring out, though. Charting his creative course was first: dabbling in hip-hop never really appealed, nor did picking up the purely R&B baton passed down by his father. The weight and texture of hard rock was always going to play its part. But his other objective of seizing control of his life would see him follow his father’s footsteps – into the United States military. Looking back at his three years in the National Guard, stationed out of Corinth, Mississippi, he recalls “the most fun that you never want to have again” as part ego-boost and part reality check.
“I remember the moment so clearly, standing in my front yard, when I decided to enlist,” he says. “Some people go into the military because they feel like they need to be straightened out. I’d grown up in a well-rounded household – I was never a bad kid – but I’d just dropped out of college and I was at a place where I didn’t know where I was going or what I wanted to do. I was hanging out with a friend a few years younger than I was, talking about doing something down the line and he told me he couldn’t because he was going to the army. I didn’t know what I wanted to do with my life so I decided to join up, too. I didn't tell my dad. I knew that he wanted me to go but I wanted to know that it was a decision I was making off my own back, rather than a mistake I could blame him for if it turned out to be something I didn’t like.”
Although a one-long-weekend-per-month commitment allowed time for music and a civilian job on the side – overseas deployment was never involved – it nevertheless instilled strength and honed confidence.
“I’ve always been a very determined person: very headstrong, naturally very confident in myself. But going through the army only intensified what already felt like an uncontrollable flame. And I don’t say that in any conceited way. The army helped me be more clear-minded; it helped me be a little more direct; it really just intensified my personality times 1000. And it taught me patience and teamwork. If I could go back in time, would I join up again? Without a moment’s hesitation.”
At the beginning of 2023, Sleep Theory were still unknowns. Their line-up had just recently been solidified, and only months earlier had they settled on a name. Posting a 17-second preview of new song Another Way to TikTok on a whim mid-January, there was little expectation. But within 36 hours it had earned a half-million views and a legion of new fans clambering for more.
‘Stops walking and immediately starts searching Spotify…’ enthused the more moderate corners of a ravenous comment section. Others were more unequivocally demanding: ‘RELEASE! IT! NOW!’
Inextricable as that moment now is from the Sleep Theory story, Cullen sees the irony in their being perceived as any kind of ‘overnight success’. Leaving the army in 2018, he was already in another Memphis band whose name he’d rather not divulge (“Imma keep that one a little hush-hush”) but as soon as local producer David Cowell came calling, and Cullen’s then-bandmates expressed their disinterest, the time came to strike out with new collaborators and a bigger vision.
“I told David that I wanted to be the Bruno Mars of the rock scene,” he remembers. “I wanted to be that kind of artist [with a defined identity] where you never know quite what they’re going to do next. David was probably the best producer in Memphis at that point, but he wasn’t in the industry. So we were able to come up together – him as a producer and Sleep Theory as a band. It’s good to see his genius get the attention it deserves!”
A studio project for the first few years, the outfit began to truly take shape with the recruitment of bassist Paolo Vergara in 2021 following a birthday bash where Cullen saw him play Paramore’s My Heart.
“He told me he just wanted to do photography at first,” the singer recalls with a smile. “But I peer pressured him into being in the band.”
Through Paolo, drummer Ben Pruitt became involved, tracking percussion on the aforementioned Another Way. Then Ben’s brother Daniel joined the fray: a formidable shredder/screamer, it was the last component around which everything clicked.
“We write collectively,” Cullen explains. “If we were making a film where you’ve got the actors and producer and the cinematographer, I guess I’d be like the director. I can’t pick up a guitar, but I can see things and hear things and understand where everything needs to go. I’ve also learned when I need to get out of my own way to let other people do their jobs. At the beginning we were still trying to figure things out, but now we’re more of a well-oiled machine.”
Assigning labels to his work can be a tricky process for Cullen. Rejecting alternative band names ‘Monolith’ (too dark) and ‘Wavelength’ (too poppy) he eventually settled on ‘Sleep Theory’ while perusing scientific terms online and seeing its component parts on opposite columns in an article online.
“It feels right. It rolls off the tongue. It doesn’t have the weight of anything else on it: heavy or soft. Truthfully, us talking about it is me figuring it out for the first time.”
Released on Epitaph, 2023’s Paper Hearts was technically an EP, but so much time and effort had been poured into its six songs that it felt more than that. Travelling back and forth to David’s Supernova Sound studio in north-east Memphis to track Afterglow, Cullen knew it needed to be a definitive statement.
“Afterglow picks up where Paper Hearts left off,” he says, laying out an impassioned but ultimately abstract emotional framework. “It gives closure to a story that we’ve been telling so far. It captures that feeling of having been through so much with someone but still being caught up between the ‘me and you’. The after effects – that afterglow – still haunts me. There are personal experiences in there, but they’re not specifically personal to me. They could come from any member of this band – or from our producer. Certainly, we didn’t go into the studio and say, ‘Okay, let’s talk about love!’ but we did want these songs to be relatable. Everyone can relate to heartbreak so, knowingly or unknowingly, we wrote about that.”
“If you come in and you’re doing TikTok trends to be a quick grab, people are going to treat you that way”
Hip-hop beats and electro atmospherics with metalcore snarl and R&B sensuality combine into a heady whole, delivering jittery adrenaline bursts, passages of fragile poignancy and others of soul-swelling catharsis. Hourglass, for instance, blends pop-punk and metalcore like peak A Day To Remember, pondering, ‘The last light of a faded glow… The fight that you’ll ever know!’ Stuck In My Head sinks colossal pop hooks into a tale of infatuation gone sour. EP holdover Numb is a crunchy anthem, defiantly ‘Looking in the eyes of a broken dream / Another new plan torn at the seams.’
No track is more keenly felt than new single III (pronounced ‘threes’), however. A tale of something being taken from the band and “soiled in the worst way imaginable”. Its inevitable earworm success will be a most satisfying revenge.
“If life gives you lemons, you should make lemonade,” Cullen smiles. “And if it gives me bad experiences like that, I’ll turn them into bangers.”
Honesty and undiluted vision is everything. Even if it’s at odds with their original viral success.
“I refuse to just take that ‘TikTok approach’,” Cullen nods. “Our manager will tell you, I don’t care about trends. I’m not here for no temporary interest. If everybody else is doing it, I don’t want to. I’m never the guy that will do a TikTok dance or create a clip that’s just an eye-grab because it’s something that people see everywhere else. That’s just fitting in with the masses.
“Even with that first teaser for Another Way, it wasn’t about having ‘the TikTok song of the summer’, it was about setting the tone for the more professional way that we want to be perceived. I refuse to [stoop to] that TikTok baseline. We’re not here to be comedians. We’re here to make art. That does not begin with being the same as everybody else.”
Independent minds are defined not by what they think, but how. There’s nothing preachy about Cullen. No inauthentic flamboyance. A remarkable lack of self-importance for an artist who’s gone so far so fast. But there is logic, problem-solving and an irresistible natural inquisitiveness. At various points in our conversation, he stops proceedings to discuss topics as varied as the nature of catharsis, the tricky UK/EU divide and the geographically-variable ingredients of a ‘chippy tea’.
Training his focus not just on the stratospheric rise of Sleep Theory but the broader booming alt. scene as a whole, and new figureheads from Spiritbox to Sleep Token, he sees a changing tide.
“With old Bring Me The Horizon, you were either into it or you very much were not,” he cuts straight to the chase. “But with newer Bring me The Horizon, there are so many different elements in play that a lot of people can find something they like. History repeats itself. Around 2009 it felt like hip-hop and pop were having a real moment. Rock just wasn’t able to keep up. Most artists weren’t doing anything to make this music digestible to a wider audience. If they were, they fell into either the Thirty Seconds To Mars and Imagine Dragons category [directly lifting from pop sounds] or they were acts like Kings Of Leon: proper bands leaning into a very poppy songwriting sensibility. As soon as you got into the heavier metalcore and screamo stuff, it was much more [of an acquired taste].
“Nowadays, heavy bands have flipped the script, making music for everyone’s ears. You might be the sort of listener who considers themselves a pop fan, but you could turn on a Sleep Token song and enjoy it. There’s a broader emotional range, too: it’s not all about sadness and dark subject matter, it’s more relatable, taking in the broad range of feelings that older bands did.”
Breaking into massive rooms alongside Beartooth and going on to share stages with everyone from Wage War to Nothing More to Hollywood Undead, Sleep Theory have proven themselves capable of mixing it with the current heavyweights. Still, Cullen looks to the bands he grew up spinning to guide his way. Challenged to name three favourites, he triples down.
“I could say Linkin Park, Fall Out Boy and Paramore,” he replies. “But I could also say Disturbed, Three Days Grace and Saosin. Or Scary Kids Scaring Kids, Woe, Is Me and Dance Gavin Dance. There are far too many variables for me to narrow it down to just one. Or even three.”
First and foremost, Cullen is a fan, and seeing others feel that fandom for his own band holds pride of place in his mind. Sure, streaming metrics and tickets sold can demonstrate Sleep theory’s success, but the electricity of interpersonal connection is worth more than fame or fortune.
“Becoming a ‘big band’ is about being able to shift people’s minds,” he says. “In some small way, that’s changing people’s lives. I realised things were changing for Sleep Theory at a concert a while back. This guy substantially older than I was came up to take a picture with me. I noticed he was shaking, and I asked if he was okay. He said he was nervous ‘because he was meeting his hero.’ I knew the music was having an impact on people but in that moment it really hit me. It was humbling, but also difficult to get my head around. I’ve spent my whole life looking up to people older than me. Now I have people who’ve lived longer and experienced more saying that they look up to me!”
Ultimately, of course, nothing is more important than satisfying himself. Above all the other influences, Cullen cites slinky Atlanta metalcore trailblazers Issues, specifically 2019 landmark Beautiful Oblivion, as the template he most wants to emulate. It’s an all-killer record in his eyes, and he imagines an end-point for his own career where his catalogue remains unblemished by the presence of any hint of filler. Paradigm-shifting as Sleep Theory’s trademark sound may be, there would be no more satisfying legacy than never allowing his high standards to slip.
“I grew up listening to artists like Michael Jackson,” Cullen explains. “I’m never going to be the guy to say, ‘That’s good enough.’ I don’t want to have average songs. I don’t want songs that are just going to get me by. I don’t want songs where people are looking at my catalogue and saying, ‘All these are great, but that one could have been better…’ If someone else can see that, I can too. And as much as I want to give our fanbase what they want to hear, I’m never going to give them anything that I don’t.
“The defining quality of this record is that it was still made without the weight of outside influence: four guys and our producer in a studio just writing what we love before we even think about giving it to anyone else. People have grown so used to this idea of artists catering to their listeners. I’m not catering to anybody. I’m gonna do what I want. I’m gonna be true to myself. Either you jive with it or you don’t. I’m never going to bend to anyone else’s whims. I can’t. That’s legitimately the way I’m wired.”
Afterglow is released on May 16 via Epitaph. Get your exclusive Kerrang! x Sleep Theory T-shirt now.
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