Mills released his first song on
MySpace when he was in the seventh grade.
2009–2013: Beginnings and formation of Goth Money Records Mills began making music "'round 2009/2010 just bullshittin' 'round on a laptop mic." Around 2012, Mills began to form Goth Money Records alongside Karmah and Hunned Mill ( Hunned Stackz) whom he met in school. He then met Marcy Mane ( MFK) over
YouTube when searching for
trillwave beats. In 2012, Mills released multiple notable projects, including
Crack Cloud$ Over Art$$ Kitchen, a project which would later be instrumental in solidifying him as a major actor in the underground rap scene. After moving to
Los Angeles, California, in 2013, he met Kane Grocerys ( YSB OG). Luckaleannn then joined after meeting Mills over the internet. At some point, L.V.X. joined, whom he also met in school.
2014–2016: Collaborations with Drain Gang and Working on Dying Around 2014, Mills began receiving more widespread attention. In a review of the 2014 mixtape
City of Doves, the music publication
Tiny Mix Tapes wrote "the tape slaps from top to bottom with tear-jerking, uzi toting emo-thug anthems". By 2014, Mills had also met the Swedish cloud rap collective
Drain Gang members
Yung Lean and
Bladee, as well as the producer collective
Working on Dying. These collaborators would all be instrumental in the upcoming years of his career. 2014 also marked the release
700 Dagreez, featuring "Stevie J and Joseline" and a collaboration with Bladee, "7 Roses", which would both become fan favorite songs over time. The mixtape included production from
Yung Sherman,
Suicideyear,
Cold Hart, and members of the Working on Dying collective. Mills, through his collaborations with the Working on Dying collective and its founder
F1lthy in particular, would be credited as being instrumental in the development of the Tread genre, a subgenre of
Trap music that became popular around the mid-2010s. Collaborations became limited after
Hippos in Tanks' founder and frequent Drain Gang collaborator Barron Machat died in a car crash on April 8, 2015. Mills nonetheless worked with Yung Lean on his 2016 album
Warlord, appearing on the song "Pearl Fountain" along with Bladee. In 2017, Mills also made an appearance on Bladee's
Working on Dying mixtape, produced by the collective.
2016–present: Sickboyrari On July 14, 2016, Mills released the
Working Out da Mud mixtape, crediting himself as 'Black Kray AKA SickboyRari'. Mills explained the choice of new name came from him being "sick" and because he "stays in his lane like a
rari". This new alias would mark his career from 2016 onwards. In a 2018 article,
Pitchfork referred to him by his new name in an article written about new songs from up-and-coming rappers. Mills has continued collaborating with the Working on Dying and Drain Gang collectives into the 2020s, as evidenced by his feature on the F1lthy-produced track "Otherside" from Bladee's 2024 album
Cold Visions.
The Fader described his verse by saying, "Rari enters late, adopting a codeine-coated delivery that allows us to imagine what
Chief Keef might sound like if he was born in the south". The publication also put the song on their list of 50 best songs of 2024. == Artistry ==