tonality vs tonus

tonality

noun
  • The quality of all the tones in a composition heard in relation to the tonic. 

  • The interrelation of the tones in a painting. 

  • The system of seven tones built on a tonic key; the 24 major and minor scales. 

  • A sound of specific pitch and quality; timbre. 

tonus

noun
  • tonicity; tone 

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