Milwaukee is not the first city that comes to mind when you think about the artists reshaping underground hip-hop. It probably is not even the fifth. But Zenon “Zen” Castillo, the 21-year-old rapper and producer who records as 1oneam, has spent the last three years quietly proving that geography is irrelevant when the music is undeniable.
Background and Journey
1oneam emerged through SoundCloud, building an audience one track at a time in a city with no established hip-hop pipeline. No industry infrastructure, no A&Rs scouting open mics, no template to follow. That isolation became an advantage. Without the pressure to conform to a regional sound, he developed something distinctly his own: a moody, melodic approach to underground rap that pulls from pluggnb, trap, and emo-rap without committing fully to any of them.
His catalog tells the story of a young artist evolving in real time. Early SoundCloud loosies gave way to more polished work, and by 2024 he had released two focused projects, One Life and One Death, that explored opposing emotional poles with intention. Each one sharpened his production instincts and vocal delivery, setting up the most ambitious release of his career.
“In a scene filled with artists chasing the same sonic palette, 1oneam brings a patience and emotional specificity that feels rare for his age.”
Sound and Style
Describing 1oneam’s sound requires sitting with the tension between the melodic and the abrasive. His production leans into atmospheric, bass-heavy beats with layered synths and dark textures, but his vocal approach often softens the edges with melodic runs and introspective bars. The result is music that hits hard sonically but carries emotional weight underneath the surface. He produces much of his own material, giving him full control over the relationship between beat and voice, and that self-sufficiency shows in the cohesion of his projects.
The pluggnb influence is there in the dreamy, reverb-soaked production. The trap influence lives in the percussion and the energy. But neither label fully captures what 1oneam does. He is building a lane that borrows from both without being reducible to either.
The “Sin Ever After” Deep Dive
Sin Ever After, released in October 2025, is 1oneam’s most complete statement to date. The 18-track collection spans 46 minutes of moody production, sharp melodies, and introspective bars. It earned a 4-out-of-5 rating from Legends Will Never Die and landed a spot in Album of the Year’s top 500 for 2025, both significant markers for an independent artist with no label machinery behind him.
The production, handled by a trusted circle of collaborators including Tdf, Perc40, Jake Hansen, and Boolymon, shifts between heavy trap percussion and ethereal pluggnb textures without losing coherence. For an artist who has been building in public since his late teens, this album feels like the first project where the ambition and the execution fully match.
“Sin Ever After is not just a collection of songs. It is a full creative statement from an artist who has spent three years earning the right to make one.”
The Numbers and the Audience
The numbers tell part of the story: 180,000-plus Instagram followers, over 135,000 Spotify followers, and a core fanbase that treats his drops like events. All of this built independently, from Milwaukee, without label support. That kind of organic growth speaks to something the metrics cannot fully measure: genuine connection. His audience did not arrive through a playlist push or an algorithm hack. They found the music because it resonated, and they stayed because it kept getting better.
What’s Next
At 21, 1oneam has already internalized lessons that take most artists a decade to learn: own your work, know your audience, and do not mistake virality for a career. He has been independent his entire career, producing his own music and controlling the creative direction of everything he releases. That level of ownership, combined with a sound that continues to evolve, positions him as one of the underground’s most interesting long-term bets. The next chapter is his to write, and if Sin Ever After is any indication, it will be worth paying attention to.
Where to Follow and Listen
Stay locked in with 1oneam across all platforms:
- Spotify: 1oneam on Spotify
- Apple Music: 1oneam on Apple Music
- SoundCloud: 1oneam on SoundCloud
- Instagram: @1oneam
- YouTube: 1oneam on YouTube
