The main character was mad at Cynthia Procter because she pretended like she did not practice the:
The main character which knew about this was Squeaky and knew this because:
This refers to the constant learning of a particular thing where formal activities are simulated with the aim of perfecting a skill.
With this in mind and from the complete question, we can see that Squeaky is mad at Cynthia because she wants everybody to believe she is a piano prodigy who does not practise to become good.
Read more about Cynthia Procter here:
https://brainly.com/question/6358217