chirl vs singing

chirl

noun
  • A kind of musical warble. 

verb
  • To emit a low sound; to warble. 

singing

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

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

  • 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 chirl and singing occurred in a corpus of books? (source: Google Ngram Viewer )