call to action vs trumpet call

call to action

noun
  • An appeal for action. 

  • A device designed to prompt an immediate response or encourage an immediate sale. 

trumpet call

noun
  • Any call to action. 

  • A call or summons on the trumpet. 

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

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