What is the average rating for all the songs?
select avg(rating) from song
How many of the songs which rating is above 9?
select count(*) from song where rating > 9
What are singer names and their countries of these songs?
select distinct t1.artist_name, t1.country from artist as t1 join song as t2 on t1.artist_name = t2.artist_name where t2.rating > 9