What is the meaning of the thick line with the 8 on top in above the photo? I have looked everywhere on the web, but can't find anything. Any help would be appreciated.
It denotes multi-bar rests. The number above the bar is the number of bars that are filled with whole rests. It's done this way to be easier to read (you don't have to be looking at the page for each specific bar) and to save paper.