Request line

A request line is a telephone line which allows listeners to call a radio station, traditionally to request the disc jockey to play a specific piece of recorded music on-air. In the late 20th century, a large volume of listener requests for a specific song could help to turn it into a hit in the United States market. By the early 2000s, radio request line data was supplemented by a changing mix of other sources, such as online surveys, to help predict future hits.