In the words of creator Andy Woodruff, "the premise is simply that each of the 88 piano keys is assigned to a single Ohio county. How the keys are mapped to the counties depends on a specified data attribute: the notes and counties are ordered by that attribute and then linked to one another. For example, if the chosen attribute is population, the county with the lowest population is assigned the lowest-frequency piano key, the county with the highest population is assigned the highest-frequency piano key, and so on. The data I have here are a little out of date, but that doesn’t matter for demonstrating the idea."
Updated or not, it is a really cool idea. Click Away!