There are 13 songs on Tee Grizzley’s debut mixtape, My Moment, but the first three minutes alone will convince you of the young Detroit native’s exceptional talent. With no instrumental, the 23-year-old beats out a drum pattern on a kitchen table, snaps his fingers, and adds his own harmonies to a rhyme about the stomach pains and betrayal he felt while serving time in two states. It drips with pathos: “I sat there and waited/For niggas to help me/All that talking they did, them niggas ain’t show it/I sat there and starved/I remember the hunger.” My Moment was written during Grizzley’s incarceration, and argues for him as a sober, sincere street rapper with the potential for some crossover success.

Prior to his time in the spotlight, Grizzley, born Terry Wallace, was sentenced to 18 months for second-degree home invasion in Michigan and nine months for a jewelry store robbery in Kentucky. The former charges stem from his time at Michigan State University, where he studied accounting and finance; an acute financial crisis of his own inspired him to raid a series of dorm rooms before being caught with nearly $20,000 worth of cash and electronics. This was February 2014. Grizzley was released pending an investigation and then fled to Kentucky, where he was eventually picked up during that botched jewel heist.

All told, Grizzley’s legal troubles only lasted about two and a half years—a far cry from the 30 years he claims to have been initially offered in a plea deal. As he raps on his breakout single, “First Day Out,” which is included here: “My first offer was 30 years, not a day lower/I told them crackers, holla at me when they sober.” My Moment frequently feels like a series of formal exercises, someone taking his mind off of his immediate circumstances by diving into his work. “Catch It” could slot into most rap radio playlists, perhaps between Big Sean’s “Bounce Back” and Future’s “Fuck Up Some Commas.” “Country” is like a rapid-fire resume for Grizzley as a technical rapper, and the hook on “How Many” sounds as if it could be a reference for Ty Dolla $ign.

Speaking of those technical points, Grizzley follows in the long line of Detroit rappers whose syllables frequently spill out on either end of the bar. It’s a careening, freewheeling flow, where phrases are expanded and contracted seemingly at random, but where the sum total is a near-perfect groove. (If you’ve ever heard a Big Sean song and wondered why he’s rapping off-beat, he isn’t—he’s approximating this very approach.) There’s a bonus effect to this. A song like “Day Ones,” with its more perfectly coiffed delivery, stands out as a departure on My Moment, where on an industry-trained rapper’s record, it might get lost in the din.

As great as some of the new songs on My Moment are—see “10K”’s bounce in particular—“First Day Out” remains Grizzley’s masterwork. It’s as defiant as could be expected for a song he recorded in the same clothes he was wearing as he left prison, but it’s also somber, an elegy for those left behind behind bars or for those already departed. “First Day Out” is extraordinarily dense with names, nicknames, and references to real people in Grizzley’s life, to the point where quoting its lyrics feels invasive. Maybe that’s what’s so enrapturing about My Moment: despite Grizzley’s newfound buzz, and despite the commercial aspirations betrayed by some songs, the tape feels like it was made for his friends and family, a love letter to everything that brought him to this point, good and bad.