According to this website, a professor and archivist named Hugo Keesing put together a few seconds of every Billboard #1 hit starting in January 1956 and continuing for several decades after that. The text says that he got the idea from radio station WOR-FM in New York.
Listening to this is an interesting experience, but I gave up somewhere around 20 minutes into Part 1 when Bobby Goldsboro sang “Honey” (a #1 considered by some to be the worst song of all time).
There are obviously lessons to be learned from hearing what were the best-selling or most popular songs in America (according to Billboard magazine). My main reactions were “I remember that one” and “Wow”.