*smallville* A (clical/opera) musical question on the Luther's - (Lex &Linoel)?

I'm a devout watcher of smallville, (not a fanatic lol..just like to watch it) and I've noticed the music in some of the scenes with the Luther's (lex or Linoel). sometimes it opera and in others it's more clical like Beethoven or bach. does anyone know what the music is? I don't know but it just sounds good.. I Guess the real question is, does anyone know good clical music or opera? (solos, cello, violin, piano, flute, other instruments.) thank yous all (:P)