basso vs euphonium

basso

noun
  • An instrumental part written for a bass instrument. 

  • The double bass, or contrabasso. 

  • A bass singer, especially in opera. 

euphonium

noun
  • A valved brass instrument with conical tubing similar in appearance to a tuba but of higher pitch; a sax horn. 

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