a cappella vs moo

a cappella

noun
  • A vocal performance with no instrumental accompaniment. 

adv
  • In a manner of a choir with no instrumental accompaniment; literally, "in the style of the (Sistine) Chapel (in Rome)", such as a musical Mass done a cappella. 

adj
  • Singing solely or mainly without instrumental accompaniment. 

  • Related to a form of purely vocal music mostly associated with American college performance groups. 

moo

noun
  • The characteristic lowing sound made by cattle. 

  • A foolish woman. 

intj
  • The characteristic sound made by a cow or bull. 

verb
  • Of a cow or bull, to make its characteristic lowing sound. 

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