recitative vs vocalizing

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 

vocalizing

noun
  • vocalization 

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