A harmonic interval is the distance between two notes played simultaneously. In music theory, these intervals are measured in terms of pitch and can be described using terms like "major," "minor," "perfect," "diminished," and "augmented." Each type of interval has a unique sound and emotional quality, contributing to the overall harmony of a piece. Common examples of harmonic intervals include the perfect fifth, which spans seven half steps, and the major third, which spans four half steps. Understanding these intervals is essential for musicians and composers, as they form the foundation of chords and harmonies in various musical styles.