Intervals

An interval is the distance in pitch between two notes. Intervals are given a number name and a quality name. The number name indicates the number of tones of the diatonic scale which the distance includes. For example: c to d is a second and c to e is a third. An interval of the number one or first is called a unison and an interval of the eighth is called an octave.

Five interval qualities are possible: perfect, major, minor, diminished, and augmented. The quality of an interval is determined by the number of half steps it contains. For example: d to e-flat is a minor second (one half step) and d to e-natural is a major second (one whole step or two half steps).

The term perfect is only used in connection with unisons, fourths, fifths, and octaves. The terms major and minor are only used in connection with seconds, thirds, sixths, and sevenths. If a major interval is made a half step smaller without changing its numerical name, it becomes a minor interval. If a minor or a perfect interval is made a half step smaller without changing its numerical name, it becomes a diminished interval. If a minor interval is made a half step larger without changing its interval name, it becomes a major interval. If a major or a perfect interval is made a half step larger without changing its numerical name, it becomes an augmented interval.



Intervals (Major and Minor Scales)

The intervals from tonic (first note) to each of the other notes within a major scale are either major or perfect. The intervals of the third, sixth and seventh change to minor in a minor scale.

                       
                    
                 





Examples of Intervals

Perfect Unison (P1) = 2 notes on the same pitch
Minor Second (m2) = 2 adjacent notes a half step appart
Major Second (M2) = 2 adjacent notes a whole step appart
Minor Third (m3) = one and one half step (M2 + m2)
Major Third (M3) = two whole steps (M2 + M2)
Perfect Fourth (P4) = two and one half steps (M3 + m2)
Augmented Fourth (A4) = three whole steps (M3 + M2)
(Also called a tritone)

Augmented Unison (A1) - Sounds like a minor second.
Diminished Second (d2) - Sounds like a unison.
Augmented Second (A2) - Sounds like a minor third.
Diminished Third (d3) - Sounds like a major second.
Augmented Third (A3) - Sounds like a perfect fourth.
Diminished Fourth (d4) - Sounds like a major third.

Diminished Fifth (d5) = three whole steps (m3 + m3)
(Also called a tritone)
Perfect Fifth (P5) = three and one half steps (M3 + m3)
Minor Sixth (m6) = four whole steps (P5 + m2)
Major Sixth (M6) = four and one half steps (P5 + M2)
Minor Seventh (m7) = five whole steps (P5 + m3)
Major Seventh (M7) = five and one half steps (P5 + M3)
Perfect Octave (P8) = six whole steps (P5 + P4)

Augmented Fifth (A5) - Sounds like a minor sixth.
Diminished Sixth (d6) - Sounds like a perfect fifth.
Augmented Sixth (A6) - Sounds like a minor seventh.
Diminished Seventh (d7) - Sounds like a major sixth.
Augmented Seventh (A7) - Sounds like an octave.
Diminished Octave (d8) - Sounds like a major seventh.
Augmented Octave (A8) - An Octave + a half step.