breviary vs psalmody

breviary

noun
  • A book containing prayers, hymns, and so on for everyday use at the canonical hours. 

psalmody

noun
  • A collection of psalms. 

  • The singing or the writing of psalms. 

verb
  • To celebrate in psalms. 

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