Hot Rock Songs is a record chart published by Billboard magazine. From its debut on June 20, 2009, through October 13, 2012, the chart ranked the airplay of songs across alternative, mainstream rock, and triple A radio stations in the United States. However, since the chart dated October 20, 2012, the Hot Rock Songs chart has followed the methodology of the Billboard Hot 100 by incorporating digital download sales, streaming data, and radio airplay of rock songs over all formats. Before that date the chart was ranked by overall audience impressions (the approximate number of audience impressions made for each play, as determined by BDS data cross-referenced with Arbitron listener information).