Defining the Song of the 20th Century
The designation of the "song of the 20th century" is a factual ranking based on major industry polls and public performance data. The Recording Industry Association of America (RIAA) tracks multi-decade sales and streaming figures, which consistently place a specific track at the top of historical charts. This song's dominance is measured by cumulative units sold and radio airplay across multiple generations. For a detailed breakdown of how these metrics are compiled, see the RIAA's official methodology page