mezzo-soprano vs soprano

mezzo-soprano

noun
  • A voice or voice part intermediate in compass between soprano and contralto. 

  • A person having such a voice. 

soprano

noun
  • Person or instrument that performs the soprano part. 

  • Musical part or section higher in pitch than alto and other sections. 

verb
  • To sing or utter with high pitch. 

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