what nuance does ことがありますか add in this sentence?


Sentence 1: 先生、この歌をお聞きになったことがありますか。  
  
I thought it can just be  
Sentence 2: 先生、この歌をお聞きになりましたか。

Is sentence 2 wrong? If it's not, what's the difference in nuance between
those two?




Not wrong. The difference is same as in English.

> Sentence 1: この歌をお聞きになったことがありますか。
>
> Sentence 2: この歌をお聞きになりましたか。

These can be translated to

> Sentence 1: Have you heard this song?
>
> Sentence 2: Did you hear this song?

The first one puts emphasis on the experience and the second one on the fact
(not so long time ago).

It is natural for 先生 to answer "Yes, when I was 5 years old." for the first
one, but this answer sounds strange for the second one. If 先生 answers "Yes,
last week.", it sounds natural for both.




Not wrong. The difference is same as in English.

> Sentence 1: この歌をお聞きになったことがありますか。
>
> Sentence 2: この歌をお聞きになりましたか。

These can be translated to

> Sentence 1: Have you heard this song?
>
> Sentence 2: Did you hear this song?

The first one puts emphasis on the experience and the second one on the fact
(not so long time ago).

It is natural for 先生 to answer "Yes, when I was 5 years old." for the first
one, but this answer sounds strange for the second one. If 先生 answers "Yes,
last week.", it sounds natural for both.

