Intervals have two characteristics: the type or quality of an interval (ex. major, perfect, etc.) and the size or distance of an interval (ex. second, third, etc.). To determine an interval, you first look at the type of interval followed by the size (ex. Maj7, Perfect 4th, Maj6, etc.). Intervals can be major, minor, harmonic, melodic, perfect, augmented and diminished.
Sizes or Distance of Intervals (Using the C Major Scale as example)
When determining the interval between two notes, you need to count every line and space starting from the bottom note going to the top note. Remember to count the bottom note as #1.
- Prime/First - c to c
- Second - c to d
- Third - c to e
- Fourth - c to f
- Fifth - c to g
- Sixth - c to a
- Seventh - c to b
- Octave - c to c
Types or Qualities of Intervals
- Perfect Intervals have only one basic form. The first (or prime), fourth, fifth and eighth (or octave) are all perfect intervals. When you lower a perfect interval by a half step it becomes diminished. When you raise it a half step it becomes augmented.
- Non-perfect Intervals have two basic forms. The second, third, sixth and seventh are non-perfect intervals; it can either be a major or minor interval (ex. Maj7, minor6, etc.). When you lower a major interval by a half step, it becomes a minor. When you raise it a half step it becomes augmented. On the other hand when you lower a minor interval by a half step it becomes diminished. When you raise it a half step it becomes a major.