An effective chart can answer many questions, but it can never answer all questions. It might answer the exact question the chart designer wanted to answer, but even the most astute designer cannot control his or her audience. A curious audience will read a chart and, with luck, come up with new questions.
Once upon a time everyone knew who was No. 1. My mates, my Mum and probably your Mum too - knew if Blur had beaten Oasis, and whether the Spice Girls had managed to get their sixth chart topper in a row. Now that's no longer the case. Unless it's the Christmas No. 1, with its attendant media hoopla, the specifics of who exactly is heading the charts often passes us by.