Text: An interval is the distance between two notes. An interval is also the combination of these two tones. The quality of an interval is determined by its size and by the relationship of its position to the keynote or Fundamental. There are five types of intervals: Major, Minor, Perfect, Diminished and Augmented. A Major interval contracted by lowering the upper note or raising the lower note by one half step becomes Minor, and contracted another half step becomes Diminished.

See Also:

Source: