lead sheet vs symphony

lead sheet

noun
  • A form of written music that specifies the melody, lyrics, and harmony. 

symphony

noun
  • Harmony in music or colour, or a harmonious combination of elements. 

  • An instrumental introduction or termination to a vocal composition. 

  • An extended piece of music of sophisticated structure, usually for orchestra. 

  • A symphony orchestra. 

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