Its all the original shows just the way they aired back in the seventies,hosted by Casey Kasem.

In 1970, working with childhood friend and Hollywood producer Don Bustany, Kasem proposed a countdown radio show loosely based on the 1940's and 1950's hit show Your Hit Parade. The result was American Top 40 which debuted on July 4, 1970 on 7 radio sations. Here is a video of one of the biggest songs of 1971.