question: What are the names of all songs that have a lower rating than some song of blues genre?
#1 return songs 
#2 return genre of #1 
#3 return #1 where #2 is  blues 
#4 return ratings of #3 
#5 return ratings of #1 
#6 return #1 where #5 is  lower than any  #4 
#7 return the  names of #6