Mirror of chromatic scales

A chromatic scale may received a mirror whose any note can act as pivot but the mirror has to be in the tonality of the whole tone scale. Only the first half of a chromatic scale appear in one direction as pivot so the original chromatic scale must have to separated part

  • from tonic to triton
  • from triton to tonic
  • In the descending chromatic scale the slope of the pivots line is inverted.

    All tonalities of the mirror are available thanks to another chromatic scale starting on C# that provides the second whole tone scale.

    Caution:E scale as mirror is different from the E chromatic scale.
    Here the E scale is the mirror of a C chromatic scale with D as pivot

    Now E is the mirror of a E chromatic scale with two pivots E and Bb

    Therefore to start a chromatic scale with another degree one must define the whole tone scale and the triton

Mirror of transposed church modes

Don’t get confused ! Up to now we worked on the C Major scale starting on each scale degree(Church modes) mirrored by various scales having each scales degree as common tone (pivot) resulting in different tonalities (transposed scales) that begin with different scale degree (modes).

For example:

Let’s write the mirror of a CM scale starting on F (=Lydian mode)F.G. A.BC.D.E.F

with G as  common tone (pivot)

the mirror is a Bb Maj scale (transposed scale one tone below)which begins ont its 7th degree (A Locrian mode)

Now  we are discussing the transposed original scale (the previously CM scale). The issue is  a mere shifting of the tonal center on the fifths series but carrying it into effect might be difficult due to enharmony.

Let’s go back to C major. The so called tonal center C is flanked by 6 fifths on either side

the outer enharmonic fifths close the fifths circle and share the location of the pivot forming the characteristic Triton of CM (F-B)

Remember   the pivots are the seven fifths of CM starting a fifth below the tonic and distributed  every to fifths (FCGDAEB) placed on Gb-Ab- and so on
In C Maj

Ib Bb

Notice the big zone of enharmony and  common zone that shares the Triton and is a source of difficulty.

Transposition  a tone below is a shift of two fifths to the left

Transposition  a tone above is a shift of two fifths to the right

Notice the how the transposed G dorian mode appears .

  • Some pivots are common to CM SCALE but the associated tonalities are shifted in opposed direction to transposition
  • The relation of the modes are the same

  • Taking transposition into account ,other properties are similar to the CM mirror

  • Example -1
    Mirror tonality similar to original scale

  • The pivot is the tonic of the mirror
  • note that starts the Mirror in the same tonality

    Pivots and related tonalities

    Since scales have common pivots with different associated tonality, we need a mean to know which scale we are in.

    Pivots are the 7 scale degrees in a ascending fifths series form.Each pivot is related to a specific interval with the associated tonality according to their scale function shown in the following table.

    For example let’s take the CM scale

    With G the associated tonality is Bb : a minor third above so G Is the V of the original scale(C).
    Now let’ examine DM scale

    G is associated to Ab (a second minor above) therefore G is the IV of the original scale(D)

    With A as pivot
    – A-D =a fourth so a VIth degree in CM
    -A-C=a third so a Vth degree in DM