skirl vs wind instrument

skirl

noun
  • A shrill sound, as of bagpipes. 

verb
  • To make a shrill sound, as of bagpipes. 

wind instrument

noun
  • Any musical instrument that produces sound when air flows through it; a woodwind instrument or brass instrument. 

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