WEDNESDAY, October 9, 2019

Once this was about perfection…

In general perfect intervals are the easiest to read. They are sort of WYSIWYG – What You See Is What You Get. They are not confusing to read. Long ago you were not allowed to end a composition except on a perfect 5th, an octave or unison. There is a long, complicated story behind the label “perfect”, and you can research this if you are interested. But it has nothing to do with hearing intervals. A practical trick for remembering which intervals are perfect is that they are either on the outside of an octave, like unisons and octaves, or nearly in the middle. They also have no alt names that are necessary or practical for reading.

A 5th is perfect…

A perfect 5th will always have 5 letters. It will always sound like a perfect 5th. What you hear, what you see in your hands and what you read all make logical sense. Perfect 5th, 5th and 5 are all the same thing.

A 4th is perfect…

A perfect 4th works the same way except that it is an upside down or flipped 5th. For example, C to G is a perfect 5th, but G to C is a perfect 4th. Perfect 4th, 4th and 4 are all the same thing.

A unison is perfect…

A unison is really just one note played by two people or played on two different manuals on a keyboard instrument. Perfect unison and unison are the same thing.

An octave is perfect…

An octave is perfect because both notes are the same letter and sign (# or b).Perfect octave and octaves mean the same thing. In general we use the shorter names, so unison, octave, 5th and 4th are all you need.

Here are all the perfect intervals:

  • 5th
  • 4th
  • Unison
  • Octave

Remember, you don’t need to say “perfect”…

People know what we are talking about without the extra word, so just get used to these simple terms.


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