The first recorded pop music chart "top twenty" can be traced back to the 1940s. The exact year is not clear, as different sources offer different dates. However, the concept of a music chart, or a ranking system that lists popular songs based on their sales and airplay, has been in existence for several decades.
One of the earliest examples of a pop music chart was the "Hit Parade," which was first published by the music trade publication "The Billboard" in 1936. This chart was based on the number of spins (or airplays) that songs received on the radio, as well as their sales in sheet music form. The "Hit Parade" was initially a top ten chart, but it eventually expanded to include a top twenty list.
Another early pop music chart was the "Cash Box" chart, which was first published in 1942. This chart was similar to the "Hit Parade," but it also included data from jukebox plays in addition to radio airplay and sheet music sales. The "Cash Box" chart was also a top twenty chart.
It's worth noting that these early charts were not solely focused on pop music. They included a wide range of genres, including country, jazz, and swing. It wasn't until the 1950s and 1960s that the pop music chart became more focused on the youth-oriented, commercially-driven genre that we now know as pop music.
In terms of the first "official" pop music chart, the "Billboard Hot 100" is widely considered to be the preeminent chart for pop music in the United States. The "Hot 100" was first published in 1958 and has been the go-to chart for pop music ever since. The "Hot 100" is based on a combination of sales data, airplay data, and streaming data, making it a comprehensive representation of the most popular songs in the country.
In conclusion, while the exact year of the first recorded pop music chart "top twenty" is not clear, the concept of a music chart has been in existence for several decades. The "Hit Parade" and the "Cash Box" were two of the earliest examples of pop music charts, while the "Billboard Hot 100" is widely considered to be the first official pop music chart.