bar line vs barring

bar line

noun
  • A vertical line in musical notation used to separate two bars or measures. 

  • Synonym of crossline (“type of headline”) 

barring

noun
  • Bars; an arrangement or pattern of stripes or bars. 

  • The act of fitting or closing something with bars. 

  • Timber used for supporting the roof or sides of shafts. 

  • The sewing of a decorative bar or tack upon a fabric or leather. 

  • The exclusion of someone; blackballing. 

prep
  • Unless something happens; excepting; in the absence of. 

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