miserere vs sacred song

miserere

noun
  • A small projecting boss or bracket on the underside of the hinged seat of a church stall, intended to give some support to a standing worshipper when the seat is turned up; a misericord. 

  • An expression of lamentation or complaint. 

  • Ileus. 

  • A medieval dagger, used for the mercy stroke to a wounded foe; misericord. 

sacred song

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