a cappella vs chatter

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. 

chatter

noun
  • The vocalisations of various birds or other animals. 

  • The vocalisations of a Eurasian magpie, Pica pica. 

  • One who chats. 

  • The sound of talking. 

  • The situation where a drill or similar tool vibrates and tears the material rather than cutting it cleanly. 

  • An intermittent noise, as from vibration. 

  • In national security, the degree of communication between suspect groups and individuals, used to gauge the degree of expected terrorist activity. 

  • A user of chat rooms. 

  • Talk, especially meaningless or unimportant talk. 

verb
  • To talk idly. 

  • To make a noise by rapid collisions. 

  • To utter sounds which somewhat resemble language, but are inarticulate and indistinct. 

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