Hi Sivai,
Part of your answer is in your own quote:
Quote:
Though Mozarat is dead,the fact that he spent most of his life in Salzburg is still true
That fact is true and can be referred to in present tense.
However, as the book explains, Mozart is dead and that has no effect in the present. Similarly, his life that was in Salzburg is also a part of history. It does not have a continuing effect.
If you make a sentence about his life's work i.e. effects of his living in Salzburg, his music, then perhaps you can make a sentence using present perfect.
Hope this helps
Regards
Sunil