Scales 1

To begin a lesson on scales we must segue into it by first continuing our discussion on intervals and from there we will show how an understanding of intervals is essential to an understanding of scales while simultaneously showing how an understanding of scales clarifies why intervals are classified and organized the way they are.

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The Core Intervals And The Major Scale

If you look back at the interval lesson I said that there are seven core intervals that are the basis of the Major scale and the basis of the names of all the other intervals. They are:

  1. Major 2nd
  2. Major 3rd
  3. Perfect 4th
  4. Perfect 5th
  5. Major 6th
  6. Major 7th
  7. Octave

If you will look at a piano keyboard and then from C for example, count up a Major 2nd (C to D) and then go back to the same C and from there now count up a Major 3rd (C to E) and then again go back and count up a Perfect 4th (C to F) and so on….you will have outlined the C Major scale. The formula of “stacking” these seven intervals makes a major scale no matter which note you start on. In steps the formula from any note would be:

one/ one/ one half / one / one / one / one half

Go to the keyboard and count it out and you will see that from C for example, the above scale step formula or stacking of intervals will give you C, D, E, F, G, A, B, C which is the  C Major scale. Scales are always defined and illustrated by steps and/or stacks of intervals and because chords are a derivative of scales, originally a happenstance of melodies being heard simultaneously on top of each other you have to understand both to correctly understand either.

Now to understand why the other intervals (not the core seven) are named what they are, we need to understand the five rules that govern the names or “quality” (Maj, min, Dim ect…) of intervals.

  1. If you flat a major interval the resulting interval is always minor.
  2. If you flat a minor interval the resulting interval is always diminished
  3. If you flat a perfect interval the resulting interval is alway diminished
  4. If you sharp a major interval the resulting interval is always augmented
  5. If you sharp a perfect interval the resulting interval is always augmented

By flat I mean reduce in size by 1/2 step and by sharp I mean increase in size by 1/2 step. Whenever you are required to alter the quality of an interval in the manner the shown above, the numerical value of the interval does not change even though the number of steps and quality have changed. For example: In an interval such as C to E (Maj 3rd) if you sharp the E by 1/2 step, you would consider the new interval to be an augmented third (see rule three) and it would be written as C to E-Sharp (or E#) even though a sharp E is in fact an F and the number of steps have changed from 2 steps to 2 and 1/2 steps which would seem to make it a perfect fourth. This again is an example of enharmonic equivalents because an augmented 3rd has the same number of steps and therefore sounds the same as a perfect 4th but because of how differently they are used and/or arrived at, they are considered to be different intervals.

Now if you look back at the entire list of intervals and compare them against these five rules you should now understand, for example why a tritone can be considered to be an augmented fourth or a diminished fifth. This is also why, to avoid the confusion that occurs from people mindlessly making up names and descriptions of intervals,  we have a static set of intervals to serve as a foundation that you do not normally change but you do alter as is necessary. This knowledge is crucial to understanding and taking music instruction from a director, or band leader for they will often give instructions by only stating which intervals in a piece of music they want altered or added or removed. Also, you will need to understand this if you want to be able to analyse chords and scales (especially unusual ones) that you will come across in music books and sheet music. Take time to learn this before you move on.

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Inversion Intervals

The last thing I wish to write about intervals before moving directly into scales is the fact that intervals can be inverted. For example: going up the piano keyboard from left to right, C to E is a Major 3rd. The inversion of this interval, also going from left to right would be E to C which is a Minor 6th. It is important to notice that the 3rd and the 6th add up to 9 (3 + 6 = 9). Also notice that when we inverted the interval the quality changed from Major to minor. These are just two of the rules that govern interval inversions. When you invert intervals, the rules are as follows:

  1. Major becomes minor
  2. minor becomes Major
  3. Augmented becomes Diminished
  4. Diminished becomes Augmented
  5. Perfect remains Perfect
  6. The original and the inverted inversion always add up to 9
  7. An inversion of a Unison Is an Octave which also add up to 9

Both the octave and the unison are perfect intervals.

 Copyright © 2011 oliveriancross.com

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