When the major labels descended upon Chicago in hope of landing the Next Big Thing during 2012’s great drill uprising, Lil Durk was among the most promising prospects: a melody-driven, phrase-warping dynamo who turned a trio of mixtapes into a deal with Def Jam and a sizeable national buzz. His breakthrough project, 2013’s Signed to the Streets, produced a catchy street hit ("Dis Ain’t What U Want") and spotlighted his particular brand of Auto-Tuned warbling, equal parts soothing and seething.

After a rough 2014 marked by spotty appearances on the Coke Boys 4 mixtape, a lukewarm Signed to the Streets sequel, and the murder of his cousin, OTF Nunu, things continued to nosedive for Durk in the months leading up to and immediately following his Def Jam debut, Remember My Name. His manager, OTF Chino, was killed last March and his debut, which arrived shortly thereafter, grappled with the same gun violence that took his friend and colleague, only with minimal affect and an uneven, often shoddy, delivery.

Lil Durk, however, soldiered on and earned back some musical capital with the rap ballad "My Beyoncé" featuring Detroit rapper and long-rumored girlfriend Dej Loaf, which perfectly married their similarly cleansing uses of Auto-Tune—for Durk, it purges impurities; for Dej, it makes her vocals smooth and measured like pressing wrinkles from a garment. The duet was the first taste of Durk’s latest mixtape, 300 Days 300 Nights, a 19-track offering that manages to sustain interest for its duration, presenting a reinvigorated Durk, who’s the sharpest he has been in years. "Ever since I built my buzz, I don’t get the same love," he raps on "Mud." He raps like he’s trying to earn that favor back.

The main knock on Durk is that his use of Auto-Tune renders him a prisoner to melody, which, in turn, renders him one-dimensional, but he proves himself capable on bustling rap-first songs like "On Em" and "Make It Back," where he packs some of his most ferocious bars together ("Can't stand the smell of that work, that's why my brothers cook it for me/ 30k a show don't call my phone, just book it for me.") He sounds good in both traditional drill productions (courtesy of staples Chopsquad DJ and DJ L) and spacious songs with distorted vocal samples (like Christian Rock band BarlowGirl’s "Never Alone").

The unsung hero behind many of the best cuts on 300 Days 300 Nights is producer C-Sick. The Chicago beatmaker has done most of his notable work for King Louie, but he and Durk have a palpable chemistry. On "Gunz N’ Money," Durk bops through a punching track as the bottom drops out, exposing chillingly direct warnings: "Word to Nuski killer/ Word to Chino killer/ Word to Moski killer/ We know we gon’ kill ya." Durk raps about leaving the safety of his own home and venturing out into the streets on "Jump Off," which winds layers of chords into a cocoon. The tone-setting intro, led by a monologue from his father, who has been locked up since Durk was an infant, is built around a pitched-up sample of Lori Perri’s "Up Against the Wind," which seems like a fitting representation for the tumultuous environment that Durk comes from. 300 Days 300 Nights could’ve benefitted from some sort of executive producer cutting it down to its 13 strongest songs, but songs like "Believe It or Not" and "Street Nigga" are solid as far as filler goes. Few moments lack Durk’s captivating and crushing bellows or his blunt writing. This is the rapper Def Jam thought they were getting.