Pain
In Master Class, Maria describes the endurance and discipline it takes to become an opera singer, often associating success with pain. For example, she tells a story of how she once had to walk until her feet bled, comparing this anecdote to opera singing. In another passage, she says "It's not a note we're after here... It's a stab of pain," which directly connects talent and success to pain.
Music
For Maria, life is all about music, and it, therefore, makes sense that some of the key imagery in this play is about music. Maria argues that music must be inspired by "feeling, feeling, feeling," and often criticizes her students for not emotionally connecting with the character they are playing.
Cruelty
In this play, McNally describes Maria's cruelty towards her students. Although Maria is a successful singer herself, she is arguably not a great teacher. This is because she puts very high expectations on her students, without acknowledging that they already put high expectations on themselves. Maria's untactful approach is revealed when she embarrasses and singles out the students on stage, and interrupts their performances to ask for more props from the crew.
