Answer:
The connection between the two meanings of the phrase "Two Kinds" is that of the acknowledge and acceptance of the type of relationship Jing-mei and her mother had.
Step-by-step explanation:
Throughout her childhood Jing-mei resented her mother for making her try different activities like spelling, singing, specifically playing the piano, and wanting her to become a prodigy child instead of accepting her just the way she was. Jing-mei saw this as an imposition from her mother and felt her wishes weren't being respected.
She was living up to fulfill her mother's high expectations "She hoped for something so large, that failure was inevitable" she stated. She saw her mother's disappointment whenever she failed, so she just simply decided to stop trying to please her. She actually started sabotaging her possibilities as she believed she couldn't be anything she wanted to be, She could only be her.
As a child she represents the "Pleading Child"
Years pass by , and the mother offers her to take the Piano, she sees this as a sign of forgiveness to her behaviour, and she starts to feel for it as if it were a trophy she has gotten back.
The Piano becomes a symbol of their relationship as mother-daughter.
It is only as an adult that Jing-mei makes peace with the conflictive relationship she had with her mother and understands her mother's point of view and good intentions.
Once she plays both songs "Pleading child" and "Perfectly content". She accepts the relationship and makes a comparison of it having two sides just like both songs being one. She has to play it a few times, which also shows it takes time to mature.
As an adult she is "Perfectly content"