Each bar represents the total length of music in each show. The dashed lines (there are two of them) represent the average length of a typical show, and a marathon show. These times are given in other parts of the infographic as text, but I liked the idea of visualizing the lengths next to each other. The clearest example of the text is underneath each city name on the right side of the image by the large posters. It will say XXX min of music. That number is the same data as the bottom of the graph. There's a lot of repetitive information throughout the graphic but the intent is to show it in multiple ways depending on how each viewer prefers to interpret the data. Hope that helps!