Harmonic intervals are the distance between two notes played simultaneously. They are fundamental in music theory, helping to create chords and harmonies. The quality of an interval can be described as major, minor, perfect, augmented, or diminished, depending on the specific notes involved. In Western music, the most common harmonic intervals include the octave, fifth, and third. For example, a major third consists of four half steps, while a perfect fifth consists of seven half steps. Understanding these intervals is essential for musicians when composing, arranging, or performing music.