incentive vs tonal

incentive

adj
  • Inciting; encouraging or moving; rousing to action; stimulating. 

  • Serving to kindle or set on fire. 

noun
  • Something that motivates, rouses, or encourages. 

  • A bonus or reward, often monetary, to work harder. 

tonal

adj
  • Of or relating to the general character, mood, or trend of something. 

  • Employing differences in pitch (tones) to distinguish differences in the meaning of otherwise similar words (words which would otherwise be homophonic). 

  • Of or relating to tones or tonality. 

  • Employing tones that have a predictable relationship to some tonic. 

noun
  • An animal companion which accompanies a person from birth to death. 

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