a cappella vs screech

a cappella

noun
  • A vocal performance with no instrumental accompaniment. 

adj
  • Singing solely or mainly without instrumental accompaniment. 

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

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. 

screech

noun
  • A high-pitched strident or piercing sound, such as that between a moving object and any surface. 

  • A form of home-made rye whiskey made from used oak rye barrels from a distillery. 

  • Newfoundland rum. 

  • A harsh, shrill cry, as of one in acute pain or in fright; a shriek; a scream. 

verb
  • To travel very fast, as if making the sounds of brakes being released. 

  • To make such a sound. 

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