This document discusses the I-VI-IV-V chord progression, also known as the "doo-wop" progression. It is one of the most common chord progressions in popular music, appearing in many hit songs from the 1950s to modern times. The progression uses the tonic, submediant, subdominant, and dominant chords (C, Am, F, G in the key of C for example). The document provides examples of songs that use this progression and some common variations.