List all the song names and the ratings.
select song_name, rating from song
What is the maximum rating?
select max(rating) from song
Which songs have a lower rating than the average rating?
select song_name from song where rating < (select avg(rating) from song)
What about lower rating than that of blues genre ones?
select song_name from song where rating < (select max(rating) from song where genre_is = "blues")