motet vs requiem

motet

noun
  • A composition adapted to sacred words in the elaborate polyphonic church style; an anthem. 

requiem

noun
  • A musical composition for such a mass. 

  • A large or dangerous shark, specifically, (zoology) a member of the family Carcharhinidae. 

  • A piece of music composed to honor a dead person. 

  • A mass (especially Catholic) to honor and remember a dead person. 

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