Musical Scales

ROUGH, INCOMPLETE, EDIT IN PROCESS......

[last updated: 2026-09-06]
Disclaimers
Music Theory - home page
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• What is a 'scale' ?
  • A scale is a set or collection of notes, almost always ascending.
    They most often have just 7 notes, though lots of scales have fewer notes.
        As such they are a 'subset' of the complete 12-note chromatic scale that makes up a keyboard.
    It is used to compose and play music pieces.
    That is, a given song will usually only have notes from a single scale,
        though of course that 'rule' gets violated all the time.
    The notes are chosen because they 'fit together' well with each other
    and provide the emotional character that the composer desires.
  • Conventionally,

• Scale types:
  • Scales are named with a descriptor phrase that starts with the root or tonic note, followed by the words that describes the type of scale.
    eg. C-major, or C-minor, or C-minor-7th
    The 'C' is the root or tonic, and will be the first note in the scale.
    The 'major' designates the 'type' of scale.
  • List of scale types:
    Major
    minor
    7th
    major blues
    minor blues
    pentatonic

    many others ...

• Construction of scales:
  • There are two methods that can be used to create a scale:
    • follow the characteristic pattern of number of semitones between notes,
    • or follow an algorithm.

• Construct a scale using the semitone-interval-pattern method:
  • If you look at the number of semitones between notes of a scale, you can see its 'pattern'.
    For example, for a major scale, the pattern is ...
    All major scales, regardless of key, will have this same semitone interval pattern between its notes.
    .
    
    .
    • major: 2 - 2 - 1 - 2 - 2 - 2 - 1
    • minor: 2 - 1 - 2 - 2 - 1 - 2 - 2
    • major-pentatonic: 2 - 2 - 3 - 2 - 3
    • major-blues: 2 - 1 - 1 - 3 - 2 - 3
    • minor blues: 3 - 2 - 1 - 1 - 3 - 2
    • ...

• Construct a scale using the algorithm method:
  • ...

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• The major scale is the foundation of western music, and is used as a reference point for constructing other scales.
  • The algorithm for creating the C-major scale is:
    Start with the C, and play all the white keys up to the next C.
  • To build a major scale using the step-interval method:
    start from the root or tonic note,
    add successive notes that are increased by some increment,
        either a whole step (2 semitones), or a half step (1 semitone)
  • Each scale type (see list above) has a characteristic pattern of steps between each of the notes.
  • Major scales are built with the pattern:
    whole or half steps: w - w - h - w - w - w - h
    OR: number of semitones: 2 - 2 - 1 - 2 - 2 - 2 - 1
    Note: This method requires a total of 12 semitones,
    which return you to the tonic note, one octave higher.
  • So for example:
    The C-major scale will start with the root or tonic C.
    The second note will be D, an increase of 2 semitones.
    The third note will be E, an increase of 2 semitones.
    The fourth note will be F, in increase of 1 semitone.
    etc...
  • All major scales can be built using this pattern.
    Start with the tonic note, and add successive notes, increasing by the number of semitones as specified by the pattern.
    Other possible scales in addition to C include all the notes of the piano: C#, D, D#, E, F, F#, G, G#, A, A#, and B
• Construction of other scale types:
  • For example: If you want to create a C-minor scale,
    • The first method is to start with the tonic, and follow the pattern of intervals for minor scales, which is:
      2 - 1 - 2 - 2 - 1 - 2 - 2

      This will produce the C-minor scale:

      C, D, D#, F, G, A, B
    • The second method is to follow an algorithm,
      which are unfortunately poorly documented and can be confusing.
      But for a minor scale, the algorithm is straight-forward, and says:
      "Starting with the major scale (C-major = C, D, E, F, G, A, B)
      flat the 3rd degree note"

      So in C-major, the 3rd degree note is E, so flatting it, ie. replacing it with its 'flat' (E♭ = D#) will result in:

      C, D, D#, F, G, A, B
      ie. the same result as from following the interval pattern.

• Semitone interval patterns for scale types:
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• Other stuff...
  • Each 'complete' scale will contain 7 notes, (not including the duplicated octave note)
    with a total delta, from the first tonic to the next octave of the tonic, of 12 semitones.

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