eclogue vs pastorale

eclogue

noun
  • A pastoral poem, often in the form of a shepherd's monologue or a dialogue between shepherds. 

pastorale

noun
  • A play or a musical product which has a pastoral subject. 

  • An artwork that is suggestive of pastoral themes. 

  • One of the figures of a quadrille. 

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