bar line vs crossline

bar line

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

  • Synonym of crossline (“type of headline”) 

crossline

noun
  • A line that crosses other lines. 

  • A line running across an insect. 

  • A small headline running across one or more columns, but not extending to the full width of the page. 

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