American Top 40, also known as "AT40" is a internationally-syndicated radio program hosted by Ryan Seacrest. Each week, the top 40 songs are counted down from 40 to 1.

The show began on June 4, 1970. Hosted by Casey Kasem, the show began as a three-hour program which counted down the top 40 songs on Billboard's Hot 100 Singles chart. Although the success of the show was uncertain, the show quickly gained in popularity. It expanded to a four-hour program in the late 1970s and by the early 1980s, the show could be heard on more than 500 stations in the United States alone.

In 1988, Kasem left the show due to contract concerns. His last show aired on August 6, 1988. Kasem was replaced by Shadoe Stevens, whose first American Top 40 show aired on August 13, 1988. Kasem went on to join the Westwood One radio network and start a rival show, Casey's Top 40, less than a year later. Many listeners were upset by Kasem's departure and, as a result, many stations dropped American Top 40 in favor of Casey's Top 40 once it hit the airwaves in early 1989.

During Kasem's run as host of the show, they were several features. The most famous was the Long Distance Dedication, which had evolved from a song that Kasem had recorded in the mid 60s. The Long Distance Dedication feature began when the show expanded to 4 hours in 1978. Most shows featured 2 LDDs. This feature endured on AT40 into Shadoe Stevens run as host of the show and has also followed Casey (first as the "Request and Dedication") on his Westwood One shows and then back as the LDD when he returned to AT40 in 1998. AT40 also featured several question letters a show, where a listener would write asking a chart trivia question. Sometimes these letters led to an extra being played, though this became less common as songs got longer in the 1980s. Finally, each show would often have "stretch" stories, which were stories told before playing a song that sometimes barely related to the song itself.

As the show started to lose stations once Shadow Stevens took over, several other features were tried, including interview clips and previews of upcoming chart hits. Despite these efforts, American Top 40 was cancelled on January 28, 1995.

American Top 40 was revived on March 28, 1998 with Casey Kasem once again hosting. In addition, two American Top 20 shows were created; one based on the Hot Adult Contemporary format and the other based on the Adult Contemporary format, both hosted by Kasem.

On January 10, 2004, Ryan Seacrest took over the hosting duties of American Top 40 from Kasem, although Kasem would continue to host the two American Top 20 shows. Around this time, American Top 40 became more interactive, involving online song voting and e-mails being read on-air.

See also

• Top 40

External links

• American Top 40 official website (http://www.at40.com/)
• Sample MP3 clip from American Top 40 (http://www.premieredemos.com/premiere_programming/american_top_40.htm)
• AT40 fun and games site (http://http://www.angelfire.com/music4/at40coc/) - features alot of info, including a list of Long Distance Dedications