Minor, Diminished, and Augmented Intervals

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Contd... On INTERVALS

A chromatic half step is a half step written as the same note twice with different accidentals (i.e., G - G #), while a diatonic half step is a half step that uses two different note names (i.e., G# -A ).

Major and perfect intervals may be augmented (increased in size) or diminished (reduced in size) by either type of half step to change their qualities.

Major and perfect intervals become augmented when the upper note is raised by a half step, or the lower note is lowered by a half step. The process may be referred to as augmentation.
Eg.
Major 6th on C  (C  -  A)
Augmented 6th (C -A#) OR (C♭ - A♮)






Eg.2

Major 5th on C (C - G)
Augmented 5th (C -G#) or  (C♭ - G♮)


Note:
*An augmented interval becomes doubly augmented when the upper note is raised by a half step, or the lower note is lowered by a half step.

*When a major interval is diminished by a half step it becomes minor.

*Intervals can be made smaller by placing a ♭before the upper note or a # before the lower note.

*Through diminution, minor and perfect intervals become diminished.

*A diminished interval becomes doubly diminished when the upper note is lowered by a half step or the lower note is raised by a half step.







It is possible for notes and intervals to have different names in spite of containing the same number of half steps and producing the same sounds.
For instance, an augmented 2nd above C is D#, and a minor 3rd above C is E♮.  Both intervals contain three half steps, but occur in different situations. This intervals are referred to as Enharmonic equivalents.




To be continued...