daven vs descant

daven

verb
  • to recite the Jewish liturgy; to pray 

descant

verb
  • To sing or play a descant. 

  • To discuss at length. 

noun
  • A lengthy discourse on a subject. 

  • A counterpoint melody sung or played above the theme. 

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