In music theory, an interval is the distance between two notes. It is a way to describe the pitch relationship between two pitches. Intervals are usually measured in terms of the number of letter names they encompass, as well as the quality, which describes the specific characteristics of the interval (such as major, minor, augmented, or diminished). For example, the interval between C and E would be called a major third, while the interval between C and D# would be called an augmented second. Intervals can also be described as ascending or descending, depending on the direction of the pitch movement.
