si vs ti

si

noun
  • A syllable used in solfège to represent the seventh note of a major scale. 

ti

noun
  • A syllable used in solfège to represent the seventh note of a major scale. 

  • The good luck plant (Cordyline fruticosa), an evergreen shrub. 

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