James is a self-taught piano tuner who marries a young Lebanese girl and settles on Cape Breton Island. He is opportunistic and prone to sudden anger, eventually building a profitable bootlegging operation during Prohibition. His dangerously obsessive fixation on his eldest daughter drives much of the family's dysfunction and forces them to hide dark realities behind a facade of normalcy.

Kathleen is the highly talented eldest daughter of the Piper family. Dreaming of becoming a world-class opera singer, she moves to New York City to study voice and escape the claustrophobic environment of Cape Breton. In the city, she discovers personal and artistic freedom as she explores the vibrant Harlem jazz scene.

Mercedes is the pious, rule-abiding middle daughter of the Piper family. Driven by a strict adherence to her Catholic faith, she abandons her dreams of attending college to act as a surrogate mother to her siblings. She views the world through a lens of rigid morality and self-denial, hoping to secure spiritual salvation for her troubled household through rigorous penance.

Frances is the wild, fiercely independent third daughter of the Piper family. She frequently skips school, flouts Catholic rules, and eventually finds work entertaining patrons at a local speakeasy. Beneath her cynical and abrasive exterior, she is fiercely protective of her younger sister and highly observant of the secrets that govern her household.

Materia is a thirteen-year-old Lebanese girl who elopes with James Piper, resulting in a permanent estrangement from her wealthy, conservative family. She struggles to adapt to early motherhood and watches with growing despair as her husband becomes increasingly distant from her while developing an unhealthy attachment to their eldest daughter.

Lily is the youngest member of the Piper household, surviving a chaotic delivery and a bout of polio that leaves her reliant on a heavy leather leg brace. Raised to believe she is James and Materia's child, she experiences vivid dreams and strange trances that lead her deeply Catholic sister Mercedes to view her as a potential faith healer.

Ambrose is Kathleen's infant son who dies tragically during an impromptu, chaotic baptism attempt at a creek behind the family home. Following his death, his existence is covered up by the family, though his memory haunts his surviving sisters and manifests in Lily's dreams.

Rose is a highly skilled Black jazz pianist living in Harlem. She introduces Kathleen to the vibrant, syncopated world of jazz and ragtime, offering the young singer a taste of artistic and personal liberation outside the rigid confines of classical music. She often performs in men's clothing at local speakeasies.

Nicknamed Ginger for the Caribbean ginger beer he brews, Leo Taylor is a hardworking Black man who runs a delivery service and eventually works as a bootleg runner for James Piper's illicit liquor business. He is a gentle family man whose association with the Piper family brings unexpected danger to his doorstep.

Teresa is Leo's sister and a dedicated maid for Materia's wealthy parents. She is fiercely protective of her brother and his family, ultimately willing to take extreme and violent measures to shield them from the destructive chaos of the Piper girls.

Adelaide is Leo's fiercely protective wife and the mother of his children. She quickly recognizes the threat that the reckless Frances Piper poses to her family's safety and stability, taking a firm stance and issuing direct threats to defend her husband from outside ruin.

Mahmoud is Materia's wealthy, conservative Lebanese father. He reacts violently to his underage daughter's elopement with a piano tuner, beating James before forcing a Catholic marriage and completely severing ties with Materia to preserve his family's reputation.

Camille is Materia's sister who remains firmly connected to her Lebanese heritage and stays in her father's good graces. She holds a low opinion of the Piper family, particularly viewing Frances's rebellious behavior with open disdain.

Jameel is Materia's brother who operates an underground bar and speakeasy during Prohibition. Unaware of her age or true identity at first, he ends up employing his underage niece, Frances, as an entertainer at his establishment.

Ralph is a polite Jewish neighbor of the Piper family who works at his family's general store before heading off to university in Montreal. He forms a quiet, respectful connection with Mercedes, though their differing religious backgrounds create an insurmountable barrier for her strict Catholic worldview.

Giles is a retired schoolteacher employed by James Piper to act as a strict chaperone for Kathleen during her vocal training in New York. Despite her constant presence, she is largely unable to curb Kathleen's growing desire for independence and nightlife.

Nicknamed The Kaiser by Kathleen, he is a strict, demanding German voice instructor in New York. He subjects Kathleen to grueling vocal drills and emphasizes rigorous discipline, pushing her hard to prepare for an audition with the prestigious Metropolitan Opera Company.

Anthony is a young boy raised in the Nova Scotia Home for Coloured Children. Optimistic and musically inclined, he is disconnected from his true family history until a mysterious benefactor ensures he receives an education and uncovers his roots.