How the Hot 100 and Billboard 200 Charts Work

For over two decades, Keith Caulfield has been an integral part of the Billboard charts team, tabulating which singles and albums are the most popular in the United States. To be more specific, Caulfield — managing director of charts and data operations — looks after the Billboard 200, the standard bearer for an album’s performance since it was first introduced in 1956.

In the years since the Billboard 200 — and the Hot 100, Billboard‘s premiere singles chart — debuted, a lot has changed in the music industry. Music fans went from buying vinyl records at physical stores, to buying 8tracks, cassettes and CDs, to downloading singles online, to streaming music for a flat monthly rate. To keep up with how people are listening, Caulfield and the charts team at Billboard have evolved the rules