sing vs sang
We are listening to a song "Beat it" by Michael Jackson. one of my friends ask me "who sings this song?", [This song refers to " beat it"] then what will be my answer? [As we know he is not alive to sing]

1.Michael Jackson sings this song.

2.Michael Jackson sang this song.My second question is: "
"Who sings this song?" same as "who is the singer?".Is it an work of art which doesn't depend on the person's death but depend on their works that continue to exist? I am confused.Please get me clear.

Question

sing vs sang
We are listening to a song "Beat it" by Michael Jackson. one of my friends ask me "who sings this song?", [This song refers to " beat it"] then what will be my answer? [As we know he is not alive to sing]

1.Michael Jackson sings this song.

2.Michael Jackson sang this song.My second question is: "
"Who sings this song?" same as "who is the singer?".Is it an work of art which doesn't depend on the person's death but depend on their works that continue to exist? I am confused.Please get me clear.

Answer

To answer question two.

Yes they are the same type of question. And no it does not depend on the work in my view, but the artist as to whether you use "the singer is"  or "the singer was." In this example, I'd suggest the singer WAS as MJ is no longer with us ( sadly). We can no longer refer to him as IS, even if it is a song on the radio playing now in the present day, as MJ.... no longer IS... even though his work IS   still current he IS NOT=  he WAS the singer.

Answer

Michael can't performing now and also that song was recorded thing
so my answer is 2 
sange is a past verb.

Answer

2. Michael Jackson sang this song.

very good! :-)