The "I-IV-V-I" progression is a common chord sequence in music, particularly in genres like rock, blues, and pop. In this progression, the "I" chord is the tonic, the "IV" chord is the subdominant, and the "V" chord is the dominant. For example, in the key of C major, the chords would be C (I), F (IV), and G (V). This sequence creates a sense of movement and resolution, making it appealing for songwriters. The "I-IV-V-I" progression allows for easy transitions between chords, making it accessible for musicians of all skill levels. It serves as a foundation for countless songs and is a staple in music theory.