How did radio stations get AT40 on the air? During
AT40's 1st year, the show was sent to radio stations on reel-to-reel
tapes. After the 1st year, AT40 was recorded on vinyl. One side of a 33
1/3 rpm LP could hold a half hours worth of show. Thus, 4 records would
be needed for each 4 hour show. On the records, there would be the show
and promos for the show. Throughout most of the 1970s, no commercials
came with the show. Later, when ABC Networks bought the company that
produced AT40, network commercials were added to the records. The
records would be placed in a box or record sleeve and mailed
to a radio station. Each station received its own copy of the show.
After the show was aired, the items were to be destroyed. Luckily, many
radio personnel did not destroy the copies, and many exist for the
On July 1, 1989, AT40 was available on CD on the 1st time. AT40 sent a letter to radio stations about the change. Each show was 4 CDs in length, with each CD containing an hours' worth of content. Eventually, CDs replaced vinyl completely. When AT40 left American airwaves during mid-1994, other countries received CD's without network commercials.
In order for the show to play correctly on the air, DJs
had to know the exact content and program length of the show. Included
with each show was a set of cue
sheets, which lists in detail each segment of the show and the playing
time of each track. These sheets also indicated how much time the
station had to play commercials in between each segment of the
Radio station personnel also had to communicate back to AT40s owners and let them know that they did play the show. One way they could do this is by sending a proof-of-play affidavit.
Disclaimer: The above information comes from: reading Billboard Magazine (though no specific articles are knowingly quoted], listening to AT40 shows, and personal communication with Mr. Rob Durkee. This information is posted for educational purposes only. For a thorough review of AT40 history, read "American Top 40: The Countdown of the Century" by Rob Durkee.