A chord sequence is a specific order in which chords are played in a piece of music. These sequences form the harmonic foundation of a song, providing structure and emotional context. Common chord sequences, like the I-IV-V-I progression, are widely used in various genres, including pop, rock, and jazz. Chord sequences can vary in complexity, from simple patterns to intricate arrangements. Musicians often use them to create melodies and develop themes within a composition. Understanding chord sequences is essential for songwriters and performers, as they help convey the intended mood and enhance the overall musical experience.