What's the difference between Opera & Bluegrass?

In Bulegrass & Opera, boy meets girl & they fall in love.
In Bluegrass & Opera, somebody usually dies, normally the heroine.
   In Bluegrass & Opera, the hero/murderer often gets his just reward.
    In Bluegrass & Opera, the story usually ends in tragedy.
       In Bluegrass & Opera, the hero or heroine often prays by singing: Opera-Ave Maria; Bluegrass-old Gospel song.      
         But in Bluegrass, The banjo keeps on plunkitty-plunkin,' & sounding sorta happy no matter who dies & how bad things get.