Pop Airplay is a 40-song music chart published weekly by Billboard magazine that ranks the most popular songs of pop music being played on a panel of Top 40 radio stations in the United States. The rankings are based on radio airplay detections as measured by Nielsen Broadcast Data Systems, a subsidiary of the United States' leading marketing research company. Consumer researchers, Nielsen Audio, refers to the format as contemporary hit radio (CHR). The current number-one song on the chart is "Dracula" by Tame Impala and Jennie.