a cappella vs modern

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. 

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. 

noun
  • A vocal performance with no instrumental accompaniment. 

modern

noun
  • Someone who lives in modern times. 

adj
  • Pertaining to the modern period (c.1800 to contemporary times), particularly in academic historiography. 

  • Pertaining to a current or recent time and style; not ancient. 

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