brooding vs downbeat

brooding

adj
  • Deeply or seriously thoughtful. 

  • Broody; incubating eggs by sitting on them. 

noun
  • A spell of brooding; the time when someone broods. 

downbeat

adj
  • Cautiously optimistic. 

  • Sad or pessimistic. 

noun
  • The accented beat at the beginning of a bar (indicated by a conductor with a downward stroke). 

How often have the words brooding and downbeat occurred in a corpus of books? (source: Google Ngram Viewer )