Maria Callas
The woman that the play centers around (and based on the real opera diva herself), Maria is an integral character to the play who is revealed as being brave yet also fierce. She has strong opinions and beliefs that everyone should follow what she says, but it is out of her desire to make everyone be the best that they can be. However, she often is too strict and has no filter on what she will say; she is very blunt with her students.
Sophie de Palma
She is the first soprano and therefore is Maria's first pupil to teach. However, she does not make it past the first word of the song La Sonnambula that she is trying to sing before Maria stops her and informs her that she is not paying attention to the music. The relentless criticism that Sophie receives from Maria, including criticisms about her appearance and not just her voice, results in Sophie bursting into tears.
Manny
Manny is the accompanist that practices with each of the students and Maria as he plays each of their songs. However, even he cannot escape from criticism as Maria cannot remember him form the day before, so instructs him to create a distinct look so that he will be remembered. However, Manny is captivated by Maria so this criticism does not harm him, as he is strong, and instead, Maria praises him in the second act.
Sharon Graham
Sharon is the second soprano to audition. She is set to perform one of Lady Macbeth's famous opera. Before she could even step on stage properly, Maria criticizes her for not coming on stage in character. She also remarks negatively about her outfit. Maria instructs her to go backstage and begin again. Sharon goes backstage but does not appear again. Maria remains unapologetic. Sharon, however, returns later to perform. Before she could begin her performance once more, Maria interrupts and tries to sing instead but fails to portray dominance over the piece. Maria tries to give Sharon one more advice but by this point, she's had enough. She criticizes Maria for being too old and jealous of the younger generation who sing far much better than her.
Anthony Candolini
Anthony is the only tenor and male to audition. Maria asks him about his dreams. Anthony boasts that he wants to a very wealthy and famous singer. He's chosen to sing Tosca which he tries to sing but is interrupted. Maria is disappointed and tries to send him away which fails. Anthony stands his ground and demands to be heard. Maria decides to coach him a bit and after a couple of tries, she's impressed with him.