About 10 seconds after we meet for the first time, London O'Connor excuses himself to go change clothes. He returns to the lobby of Brooklyn's Rough Trade performance space minutes later in a slightly fresher-looking version of the exact same outfit he was just wearing — mustard-yellow sweater, light-blue denim jeans, beat-up white sneakers with Velcro straps — and apologizes for the delay with a charming shrug.

O'Connor, who turned 26 last month, has worn this self-chosen uniform every day for more than a year as a gesture of creative control. "It simplifies my day so I can focus on expressing myself through other mediums," he explains after we get settled in a small greenroom with exposed-cinderblock walls. He owns more copies of each item than he can count, and had boxfuls of plain white sweaters dyed the proper hue — a rich, Christo-ish Pantone 123C — to sell as merch on his latest North American tour. The practice dates to a few months after the 2015 self-release of his first album, O∆ (pronounced "circle triangle"). "I made a rule for myself when things weren't going well yet," he says. "You hit your twenties, and people tell you you have to get practical. I was like, 'Fuck that. Music is what I want to do with my life. It's my purpose.' So I told myself I would wear this same sweater until my music made more money than my parents."

O∆ is a loose concept album about O'Connor's youth in sunny, suburban San Marcos, California. Almost all of its songs are about feeling trapped and needing to escape, but the music often has the reverse effect — his warm, bleary synth-pop melodies and conversational raps create a secret world so inviting that you never want to leave. This year, more people than ever are discovering the way in, thanks to the album's re-release on midsize indie label True Panther Sounds.

That appeals to O'Connor, who dreams of speaking for a generation of disaffected young suburbanites. "The place that I grew up in has a thousand names, and it's not just in America," he says. "Sunny Side Hills, Meadow Wood Suites, Roseville Estates... Whatever the fuck it's called where you are, it's the same shit. The houses are all the same. Everything in it, down to the colors of the blades of grass, is created by man. And we need to break out of it."

The most important influence on his early life was his mom, a self-made entrepreneur who'd relocated to Southern California after coming up in Detroit. "Her intensity as a person is why I grew up in the suburbs, where I had the luxury of being bored," he says. "And I knew that I didn't have to accept my surroundings, because my parents never did." (His father died when London was a child. "We had a great relationship, it was just short," he says.)

After high school, he moved east to study at New York University's Clive Davis Institute of Recorded Music. By 2014 he was living in a small loft space in Brooklyn, making music on the cheap, doing some occasional modeling for photographer Ryan McGinley, and starting to build the foundations of his current fan base. One day that fall, he went on SoundCloud and uploaded "Oatmeal," a casually super-catchy complaint about a fictional uncle ("He don't do nothing but watch the TV / Looking like Oscar the Grouch again / But I'm scared that in him I can see me if I don't go out and live out my dreams"). It drew positive notices from critics almost immediately. "That song has no genre," O'Connor tells me. "It's just an interpretation of my surroundings when I was a kid. There's no way to know if people are gonna relate to that. It wasn't until it got picked up that I was like, 'OK, I'm not crazy.'"

Like all his music to date, "Oatmeal" was written, produced, and recorded entirely on his own, using instruments that were compact enough to fit in O'Connor's backpack. "It was the nicest equipment a kid like me could afford if he ate pasta for years," he says. "I had an OP-1 [synthesizer] that I had bought from my last paycheck at a job I hated. I got it for myself as a reward. I had a microphone that was an emulation of the microphone that The Beatles recorded with. I got the nicest [recording] interface I could, the Apollo Twin. I'm being very specific because I know some kid is writing all of this down, and I want him or her to know."

After his lease ran out at the loft in Brooklyn, O'Connor continued work on the songs that would become O∆ while crashing with friends in New York, Michigan, and Los Angeles. "That was such a fucking weird period," he says. "Literally just sleeping where I can, setting up the mic wherever, in whose-ever bedroom." The instruments came with him in the backpack, which, naturally, was in fact an indefinite series of identical backpacks: "I would wear it out and buy the same exact one. I'm so into uniforms."

The prospect of success was exciting and stressful in equal measure. "It was really intense for me," he says. "I had a lot of dreams, but I was very much in survival mode. I was like, If I can just get through this period and start putting my ideas in motion, then I can exhale — but there will be no exhaling until I get to that point. I was very hard on myself, very critical."

Seeking a feeling of connection, O'Connor tweeted out his phone number with a message to the world: "if you’re from nowhere I’m here until my cell phone explodes." He's stayed in touch since then with many of the people who responded, eventually recruiting them into an online community he calls First Wave, which currently has members in 10 countries. "None of the labels understood what I was doing yet, but the other kids like me who were finding my shit on the internet — they got it," he says. "They were texting me every day."

His belief in the power of young people's imaginations can verge at times on Silicon Valley sales pitch. "I don't make music for kids," he tells me at one point. "I make utilities for people who are going to change the world." By this he means digital music, physical albums, and assorted O∆-branded merch, but also something grander and less definable. "I don't have that much care for these ideas from previous generations that promote false humility," he adds. "I don't think that's helpful for anyone. I think that's poison to teach that to a young generation, because they have to push humanity forward."

At another point, as if to demonstrate what he means by this, he takes the voice recorder from my hand to deliver a personal message to SpaceX founder Elon Musk: "I'm going to make the music for the first travel on an interplanetary scale. I know your company is going to be behind that, and I know that in the flight there's going to need to be music. I'm going to make that music. So get at me. Reach out to me. I'm serious."

For now, O'Connor has plenty of frontiers left to conquer here on Earth, including near-constant work on a follow-up to O∆. "I'm not working out of my backpack anymore — when I'm recording, there's a lot more people involved." He smiles. "And I have the mic The Beatles used now."

Lately he's been daydreaming about how he'll decorate his permanent living space, if and when he finds one. "My bedroom will have four things in it," he says, with the same certainty he says most things. "A very nice piano, a mattress, my microphone, and a flag on the wall."

An American flag? I ask.

Of course not. He shakes his head: "A circle-triangle flag."