Recurring cast
Debra Monk as Betty Cragdale, the long-time oboist for the New York Symphony Orchestra who instantly despises Hailey
Mark Blum as Union Bob, a piccolo player for the symphony orchestra and known for bringing up the union rules
Jennifer Kim as Sharon, Rodrigo's assistant
Joel Bernstein as Warren Boyd, the concertmaster for the symphony orchestra
Nora Arnezeder as Ana Maria, Rodrigo's estranged violinist wife
John Miller as Dee Dee, the drug-dealing percussionist of the New York Symphony Orchestra
Rubio Qian as Triangle Tanya, the triangle player of the New York Symphony Orchestra
Brennan Brown as Edward Biben, an orchestra board member
Gretchen Mol as Nina Robertson, the New York Symphony Orchestra's lawyer who falls for Cynthia
Makenzie Leigh as Addison, Alex's dancing partner and roommate
Margaret Ladd as Claire, Thomas' ex-wife who dies after hearing his completed symphony
Jason Schwartzman as Bradford Sharpe, a classical music enthusiast and host of his own podcast, "B-Sharpe"
John Hodgman as Marlin Guggenheim, a purported billionaire infatuated with Hailey
Wallace Shawn as Winslow Elliott, a neurotic concert pianist
Tenoch Huerta Mejía as Manuel, Rodrigo's childhood friend
Dermot Mulroney as Andrew Walsh, a cello soloist who fraternizes with Hailey
Monica Bellucci as Alessandra, a reclusive Italian soprano living in Venice, Italy, also known as "La fiamma"
Ana María Martínez provides Alessandra's singing voice
Christian de Sica as Alessandra's manager
Bruce Davison as Hesby Ennis, a colleague of Thomas and Gloria
Sandro Isaack as Pavel, the orchestra's stagehand who becomes friendly with Gloria
Philip Jackson Smith as Mike Margusa, a friend of Hailey's whom she recruits to work for the orchestra
Christian Coulson as Sebastian, a member of Andrew Walsh's orchestra who later becomes a member of Hailey's orchestra and moves to her apartment
Cole Escola as Shawn, Hailey's roommate and a member of her orchestra who also becomes Sebastian's boyfriend
Miles Robbins as Danny/Erase Face, a DJ with whom Thomas collaborates
Matthew Maher as Alan Lawford, a colleague of Thomas at the Queens' Philharmonic
Santino Fontana as Mozart, to whom Rodrigo frequently talks in his imagination
David Turner as Liberace, briefly replaces Mozart as Rodrigo's muse
_(cropped).jpg?width=400){kind=small}
