formality vs trumpet call

formality

noun
  • Something said or done as a matter of form. 

  • A specific requirement for obtaining a legal status, conducting a transaction, etc. 

  • A customary ritual without new or unique meaning. 

  • The state of being formal. 

trumpet call

noun
  • A call or summons on the trumpet. 

  • Any call to action. 

  • A small trumpet used by hunters to imitate the vocalisations of turkeys. 

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