note-perfect vs unimpeachable

note-perfect

adj
  • Without singing or playing any musical notes out of tune or incorrectly. 

unimpeachable

adj
  • Blameless. 

  • Beyond doubt. 

  • Not able to be impeached or reproached. 

How often have the words note-perfect and unimpeachable occurred in a corpus of books? (source: Google Ngram Viewer )