Patricia Dombrowski (Danielle Macdonald), AKA Killa P, AKA Dumbo, is a 23-year-old New Jersey native working to support herself, as well as her mother and grandmother, while also aspiring to become a rapper with her best friend Jheri (Siddharth Dhananjay).
The two meet a loner named Basterd (Mamoudou Athie) who records music, and they form the group PBNJ. Despite Patti putting in work with her music and for herself, she becomes discouraged when she meets her favorite rapper O-Z (Sahr Ngaujah), who dismisses her work. She also gets fired from her job, and her Nana passes away.
Patti catches a break when a DJ she met had listened to her demo CD and submitted her name for a competition. She gets her friends together, and they perform at the competition, earning the admiration of the crowd, as well as Patti's mom Barb (Bridget Everett), who even gets in on the performance. Although they don't win the competition, Patti and her friends hear their song on the radio, which has become the most requested song.