descant vs line out

descant

noun
  • A counterpoint melody sung or played above the theme. 

  • A lengthy discourse on a subject. 

verb
  • To sing or play a descant. 

  • To discuss at length. 

line out

noun
  • an audio jack that produces an unamplified signal 

verb
  • to take part in a sports event 

  • to appear in a lineout 

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