Parnassus vs penillion

Parnassus

name
  • The home of poetry, literature, and learning. 

  • A small town in Hurunui District, north Canterbury, New Zealand, named after Mount Parnassus. 

  • A mountain in central Greece, adjacent the site of the ancient city of Delphi, that in Greek mythology was sacred to Apollo and the Corycian nymphs and was the home of the Muses. 

penillion

noun
  • The art of vocal improvisation, with a singer or small choir singing a countermelody over a harp melody; it is an important competition in eisteddfodau. 

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