a cappella vs gamut

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. 

gamut

noun
  • All the notes in a musical scale. 

  • A (normally) complete range. 

  • All the colours that can be presented by a device such as a monitor or printer. 

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