The Greatest of All-Time Pop Songs Artists and Songs rankings are based on weekly performance on the Pop Songs chart (from its Oct. 3, 1992, inception through Sept. 30, 2017). Artists and Songs are ranked based on an inverse point system, with weeks at No. 1 earning the greatest value and weeks at lower spots earning the least. Due to changes in chart methodology over the years, eras are weighted differently to account for chart turnover rates over various periods. Artists are ranked based on a formula blending performance, as outlined above, of all their Pop Songs chart entries.