Because playing the piano is not her personal desire, Jing Mei is thrown into conflict with her mother, who wants her to not only play, but to excel at piano. As Jing Mei goes through the motions of learning to play piano, taking advantage of her nearly deaf instructor, the...
text shows that people will only put their hearts into their passions and cannot be forced to love conformity.
Jing Mei outwardly conforms to her mother's wishes just to avoid some of the conflict, but she actually works pretty hard at remaining true to herself (and thereby not learning much about playing the piano):
I did pick up the basics pretty quickly, and I might have become a good pianist at the young age. But I was so determined not to try, not to be anybody different, and I learned to play only the most ear-splitting preludes, the most discordant hymns.
She keeps up this pretense for a year, and she is only discovered when she has to play at a recital. When the conflict between her outward conformity and her inner desires comes to a head with her mother, the bitterness that it has created within Jing Mei causes her to say unbelievably horrid things to her mother. In fact, she tells her that she wishes she were dead like her mother's other (very much missed) children.
Jing Mei never wanted to be the woman her mother envisioned, and she feels that she lets her down time after time in her life. Only when she is an adult with some life experience behind her can she play the piano just because she wants to. This happens after her mother has already died, and it is only at this point that she can see how their two desires could have become one beautiful melody together.