bell-ringing vs diapason

bell-ringing

noun
  • The ringing of bells, either as a pastime or for religious observance. 

diapason

noun
  • A harmonious outpouring of sound. 

  • The range or scope of something, especially of notes in a scale, or of a particular musical instrument. 

  • A tonal grouping of the flue pipes of a pipe organ. 

  • The musical octave. 

How often have the words bell-ringing and diapason occurred in a corpus of books? (source: Google Ngram Viewer )