Parnassus vs rhythmical composition

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. 

rhythmical composition

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