Billboard Hot 100 Airplay

The Radio Songs chart (previously named Hot 100 Airplay) is released weekly by Billboard magazine and measures the airplay of songs being played on radio stations throughout the United States across all musical genres. It is one of the three components, along with sales (both physical and the digital) and streaming activity, that determine the chart positions of songs on the Billboard Hot 100.

The airplay-only chart debuted as a 30-position chart on October 20, 1984. It was expanded to 40 positions on May 31, 1986, and to 75 positions on December 8, 1990.

Each week, the Radio Songs chart ranks the 100 songs with the most airplay points (frequently referred to as audience impressions, which is a calculation of the number of times a song is played and the audience size of the station playing the tune). A song can pick up an airplay point every time it is selected to be played on specific radio stations that Billboard monitors. Radio stations across the board are used, from Top 40 Mainstream (which plays a wide variety of music that is generally the most popular songs of the time) to more genre-specific radio stations such as urban radio and country music. Paid plays of a song or treatment as bumper music do not count as an impression.

During the early years of the chart, only airplay data from top 40 radio stations (mainstream, adult pop and rhythmic), adult contemporary and modern rock formats were compiled to generate the chart. However, beginning in December 1998, the chart profile expanded to include airplay data from radio stations of other formats such as R&B, rock and country. To preserve the notion of the former chart, the Top 40 Tracks chart (now defunct) was introduced at the same time.

Per Billboard (as of October 2011):

"1,214 stations, encompassing pop, adult, rock, country, R&B/hip-hop, Christian, gospel, dance, jazz and Latin formats, are electronically monitored 24 hours a day, 7 days a week by Nielsen Broadcast Data System. This data is used to compile the Billboard Hot 100."

The radio airplay data was collected on a Wednesday to Tuesday weekly cycle, but since July 2015, this has been changed to a Monday to Sunday cycle.

Singles usually enter the Radio Songs chart before any other, because in most cases, they hit the airwaves before being made commercially available online or in stores. Prior to December 5, 1998, the Hot 100 was solely compiled of songs that were commercially available. This means that songs could enter the airplay chart, but would not be eligible for the Hot 100 unless a commercial single in stores was issued. In the 1990s, numerous tracks such as "Don't Speak" by No Doubt, "Lovefool" by The Cardigans, "3 A.M." by Matchbox 20, "When I Come Around" by Green Day all did well on the Airplay chart, but were not allowed to enter the Hot 100 because no commercial single was available, even though they would have probably been significant hits on the Hot 100 without the need of a commercial single.

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