The progression of four basic chords that was used in many popular songs the 1950s and 1960s is referred to as what chord progression?

The progression of four basic chords that was used in many popular songs the 1950s and 1960s is referred to as the "50s progression" or the "doo-wop progression". This progression consists of the following four chords:

* G major

* C major

* D major

* Em minor

This chord progression is often played with a simple strumming pattern, and it is a common feature of many popular songs from the era, including "Earth Angel" by The Penguins, "Since I Don't Have You" by The Skyliners, and "Leader of the Pack" by The Shangri-Las.