Mainstream Top 40

The Mainstream Top 40 (also called Pop Songs on Billboard.com and sometimes referred to as Top 40/CHR) is a 40-song music chart published weekly by Billboard Magazine which ranks the most popular songs 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 (Nielsen BDS), a subsidiary of the U.S.' leading marketing research company. Consumer researchers, Nielsen Audio (formerly Arbitron), refers to the format as contemporary hit radio (CHR).

History
The chart debuted in Billboard Magazine in its issued date October 3, 1992, with the introduction of two Top 40 airplay charts, Mainstream and Rhythm-Crossover. Both Top 40 charts measured "actual monitored airplay" from data compiled by Broadcast Data Systems (BDS). The Top 40/Mainstream chart was compiled from airplay on radio stations playing a wide variety of music, while the Top 40/Rhythm-Crossover chart was made up from airplay on stations playing more dance and R&B music. Both charts were "born of then-new BDS electronic monitoring technology" as a more objective and precise way of measuring airplay on radio stations. This data was also used as the airplay component for Hot 100 tabulations.

Top 40/Mainstream was published in the print edition of Billboard from its debut in October 1992 through May 1995, when both Top 40 charts were moved exclusively to Airplay Monitor, a secondary chart publication by Billboard. They returned to the print edition in the August 2, 2003, issue.

Chart criteria
Songs on the chart are ranked by the total number of spins detected per week. Songs which gain plays or remain flat from the previous week will receive a bullet. A song will also receive a bullet if its percentage loss in plays does not exceed the percentage of monitored station downtime for the format. If two songs are tied in total plays, the song with the larger increase in plays is placed first.

There are forty positions on this chart and it is solely based on radio airplay. A number of Top 40 Mainstream radio stations are electronically monitored 24 hours a day, seven days a week by Nielsen Broadcast Data Systems. Songs are ranked by a calculation of the total number of spins per week with its "audience impression", which is based upon exact times of airplay and each station's Arbitron listener data.

Songs receiving the greatest growth will receive a "bullet", although there are tracks that will also get bullets if the loss in detections doesn't exceed the percentage of downtime from a monitored station. "Airpower" awards are issued to songs that appear on the top 20 of both the airplay and audience chart for the first time, while the "greatest gainer" award is given to song with the largest increase in detections. A song with six or more spins in its first week is awarded an "airplay add". If a song is tied for the most spins in the same week, the one with the biggest increase that previous week will rank higher, but if both songs show the same amount of spins regardless of detection the song that is being played at more stations is ranked higher.

Since the introduction of the chart until 2005, songs below No. 20 were moved to recurrent after 26 weeks on the chart. In the chart week of December 3, 2005, songs below No. 20 were moved to recurrent after 20 weeks on the chart. Since the issue dated December 4, 2010, songs older than 20 weeks on the chart are moved to recurrent after they drop below No. 15.

Whereas the Top 40 Mainstream and Pop 100 Airplay charts both measured the airplay of songs played on Mainstream stations playing pop-oriented music, the Pop 100 Airplay (like the Hot 100 Airplay) measured airplay based on statistical impressions, while the Top 40 Mainstream chart used the number of total detections.

All-time chart achievements
On October 19, 2017, the Mainstream Top 40 co-hosts, Gary Trust and Trevor Anderson, gave hints as to what the number 1 all-time Mainstream Top 40 song was going to be on the charts. Later that day, the top 100 all-time songs and the top 50-all time artists were released, with the number 1 all-time song being revealed as "Another Night" by Real McCoy. Shown below are the top 10 songs and the top 10 artists from each chart.

Top 10 Pop Songs of all time (1992–2017)
Source:

Top 10 Pop Songs artists of all time (1992–2017)
Source:

Most weeks on the chart
Note: *-Year when the songs ended their respective chart runs.

Longest climbs to number one
The following songs took 20 or more weeks to reach number one.

Longest climbs to the top 10
The following songs took 25 or more weeks to reach the top 10.

Artist records




Simultaneously occupying the top two positions

 * Mariah Carey: December 9, 1995
 * 1) "One Sweet Day" (with Boyz II Men)
 * 2) "Fantasy"


 * OutKast: January 31 - February 7, 2004
 * 1) "Hey Ya!"
 * 2) "The Way You Move" (featuring Sleepy Brown)


 * Pharrell Williams: July 27 - August 3, 2013
 * 1) "Blurred Lines" (Robin Thicke featuring T.I. and Pharrell)
 * 2) "Get Lucky" (Daft Punk featuring Pharrell Williams)


 * Iggy Azalea: June 28 - July 12, 2014
 * 1) "Fancy" (featuring Charli XCX)
 * 2) "Problem" (Ariana Grande featuring Iggy Azalea)


 * Halsey: February 23 - March 9, 2019
 * 1) "Without Me"
 * 2) "Eastside" (with Benny Blanco and Khalid)

Source:

Self-replacement at number one

 * Mariah Carey — "Fantasy" → "One Sweet Day" (Mariah Carey and Boyz II Men) (December 9, 1995)
 * OutKast — "Hey Ya!" → "The Way You Move" (OutKast featuring Sleepy Brown) (February 14, 2004)
 * Iggy Azalea — "Fancy" (Iggy Azalea featuring Charli XCX) → "Problem" (Ariana Grande featuring Iggy Azalea) (July 12, 2014) †
 * Halsey — "Without Me" → "Eastside" (Benny Blanco, Halsey and Khalid) (March 2, 2019)

† Iggy Azalea is the only act in Mainstream Top 40 history to replace herself at number one with her first two chart entries.

Source:

Additional artist achievements



 * Lady Gaga is the only artist to have her first six singles reach No. 1.
 * Britney Spears holds the record for the longest span between No. 1s at 12 years, seven months and four days between her first No.1 and her latest.
 * JoJo at age 13, became the youngest solo artist to have a number-one single on the chart with "Leave (Get Out)".

Most number-one singles from an album

 * Teenage Dream by Katy Perry, 6 (2010–12)
 * 1989 by Taylor Swift, 5 (2014–15)
 * FutureSex/LoveSounds by Justin Timberlake, 4 (2006–07)
 * The Fame by Lady Gaga, 4 (2009)
 * The Sign by Ace of Base, 3 (1993–94)
 * Jagged Little Pill by Alanis Morissette, 3 (1996)
 * Let Go by Avril Lavigne, 3 (2002–03)
 * Overexposed by Maroon 5, 3 (2012–13)
 * Purpose by Justin Bieber, 3 (2015–16)
 * Revival by Selena Gomez, 3 (2015–16)

Source:

Use in countdown shows
From January 9, 1993, until its last first-run show on January 28, 1995, American Top 40 used this chart as its main source after having used the Hot 100 Airplay chart since 1991.