aria vs recitative

aria

noun
  • A musical piece written typically for a solo voice with orchestral accompaniment in an opera or cantata. 

recitative

noun
  • dialogue, in an opera etc, that, rather than being sung as an aria, is reproduced with the rhythms of normal speech, often with simple musical accompaniment or harpsichord continuo, serving to expound the plot 

adj
  • of a recital 

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