incantation vs singing

incantation

noun
  • The act or process of using formulas and/or usually rhyming words, sung or spoken, with occult ceremonies, for the purpose of raising spirits, producing enchantment, or creating other magical results. 

  • Any esoteric command or procedure. 

  • A formula of words used as above. 

singing

noun
  • The act of using the voice to produce musical sounds; vocalizing. 

  • A gathering for the purpose of singing shape note songs. 

  • Disclosing information, or giving evidence about another. 

adj
  • Producing a whistling sound due to the escape of steam. 

  • Smooth and flowing. 

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