He has played the piano since he was a child.

[Alice Chu]

Please tell me if my understanding is correct.
1. He has played the piano since he was a child.
It means playing the piano is his life experience from his childhood to the present.

2. He has been playing the piano since he was a child.
It means playing the piano is his repetitive action continuing from his childhood until now.

 

[Tdol]

I am unclear what your distinction is.

 

[Tdol]

The progressive form may place a greater importance on the duration of his piano playing.

 

[Alice Chu]

Do the two sentences mean the action, playing the piano, started in the past and continues in the present?
What’s the difference between them?

 

[5jj]

Tdol has already suggested a difference.

The progressive form may place a greater importance on the duration of his piano playing.

 

[Phaedrus]

Please tell me if my understanding is correct.
1. He has played the piano since he was a child.
It means playing the piano is his life experience from his childhood to the present.

2. He has been playing the piano since he was a child.
It means playing the piano is his repetitive action continuing from his childhood until now.

I think you have captured the meaning of (2) pretty well. While it does not mean that his life up to now has consisted of one long series of repetitions of playing the piano, it does indicate that his playing the piano is something that has occurred fairly often since he was a child.

Given the subject matter, (1) tends to indicate simply that he has had the ability to play the piano since he was a child, whether or not he has regularly exercised that ability. With other subject matters, the implication would be that the activity has happened once in a while since that time. Compare:

3a) He has climbed trees since he was a child. [How sweet.]
3b) He has been climbing trees since he was a child. [My goodness. Has he become a lumberjack?]

4a) He has drunk beer since he was a child. [Interesting. Is he from Europe?]
4b) He has been drinking beer since he was a child. [Should I expect to find him at the bar in the evening?]

 

[Tarheel]

Context might make clear the difference between the two (if there is any).