B-double-flat harmonic minor scale

The Solution below shows the Bbb harmonic minor scale notes, intervals and scale degrees on the piano, treble clef and bass clef.

The Lesson steps then explain how to identify the B-double-flat harmonic minor scale note interval positions, choose the note names and scale degree names.

For a quick summary to this topic, have a look at Harmonic minor scale.

Solution - 2 parts

1. B-double-flat harmonic minor scale

The B-double-flat harmonic minor scale has 4 double-flats, 3 flats.

Warning: The B-double-flat key is a theoretical harmonic minor scale key.

This means:

> Its key signature would contain either double-sharps or double flats.

> It is rarely used in practice, because it is too complex to use.

> It is not shown as a minor key on the Circle of fifths diagram, which contains the most commonly used minor keys.

> There is always an identical harmonic minor scale that you can use in its place, which is on the Circle of 5ths.

> The A harmonic minor scale sounds the same / contains the same note pitches, which are played in the same order, and so it can be used as a direct replacement for the B-double-flat harmonic minor scale.

Middle C (midi note 60) is shown with an orange line under the 2nd note on the piano diagram.

These note names are shown below on the treble clef followed by the bass clef.

The stave diagrams above show the scale notes without a key signature, with the sharp / flat adjustments inserted before each note on the staff.

For the key signature of this scale, showing the symbols grouped correctly next to the bass or treble clef symbol at the beginning, have a look at the Bbb harmonic minor key signature.

The difference between the B-double-flat harmonic minor scale and the Bbb natural minor scale is that the 7th note position of the minor scale is raised by one half-tone / semitone.

So whereas the Bbb natural minor scale has note Abb for the 7th note, this note is raised to arrive at note Ab for this harmonic minor scale.

2. B-double-flat harmonic minor scale descending

Lesson steps

1. Piano key note names

The white keys are named using the alphabetic letters A, B, C, D, E, F, and G, which is a pattern that repeats up the piano keyboard.

Every white or black key could have a flat(b) or sharp(#) accidental name, depending on how that note is used. In a later step, if sharp or flat notes are used, the exact accidental names will be chosen.

The audio files below play every note shown on the piano above, so middle C (marked with an orange line at the bottom) is the 2nd note heard.

2. B-double-flat tonic note and one octave of notes

The numbered notes are those that might be used when building this note scale.

But since this is a scale in the key of Bbb, it is certain that notes 1 and 13 will be used in the scale.

Note 1 is the tonic note - the starting note - Bbb, and note 13 is the same note name but one octave higher.

3. B-double-flat harmonic minor scale note interval positions

The harmonic minor scale uses the  W-H-W-W-H-W½-H  note counting rule to identify the scale note positions.

To count up a Whole tone, count up by two physical piano keys, either white or black.

To count up a Half-tone (semitone), count up from the last note up by one physical piano key, either white or black.

To count up a W½ tone (whole-tone and a half), count up from the last note by 3 half-tones / semitones - shown as 3 on the piano below.

The tonic note (shown as *) is the starting point and is always the 1st note in the harmonic minor scale.

What is the difference between the B-double-flat harmonic minor scale and the Bbb natural minor scale ?

The 7th note position (or scale degree) of the minor scale is raised by one half-tone / semitone to arrive at the harmonic minor scale note positions shown above, leaving a noticeably large interval of 3 half-tones / semitones between the 6th and 7th note positions for this scale.

4. B-double-flat harmonic minor scale notes

The 7 unique notes in a scale need to be named such that each letter from A to G is used once only, so each note name is either a natural white name(A.. G) , a sharp(eg. F#) or a flat(eg. Gb).

This is needed to ensure that when it comes to writing the scale notes on a musical staff (eg. a treble clef), there is no possibility of having 2 G-type notes, for example, with one of the notes needing an accidental next to it on the staff (a sharp, flat or natural symbol).

To apply this rule, firstly list the white key names starting from the tonic, which are shown the White column below.

Then list the 7 notes in the scale so far, shown in the next column.

For each of the 7 notes, look across and try to find the White note name in the Scale note name.

If the natural white note can be found in the scale note, the scale note is written in the Match? column.

The 8th note - the octave note, will have the same name as the first note, the tonic note.

For this scale, there are 5 mismatches (Shown as m in the Match? column), whose note names will need to be adjusted in the next step.

5. Make the B-double-flat note name adjustments

The adjustment explanation below needs to be applied to every mismatch m in the above table. The first mismatch is used as an example.

The match fails when trying to find a C-type of scale note, because either this type of note does not exist in this scale, or it exists but is in the wrong position number / table row for this match.

But music theory rules allow the name of any note to be sharpened or flattened, even white note names, so since a C-type of note name is needed, the real scale note Bwill be renamed to Cb.

Of course, even though the note is named Cb, when it comes to playing the note on an instrument, the real note B is really played.

The adjustments done in this step do not change the pitch / sound of the note, only the name of the note.

After doing the adjustments to all mistmatches, all letters A..G will have been used for this minor scale, and no rules have been broken.

Note that sometimes it is necessary to adjust the note name two half-tones / semitones forward or back, which will result in an adjusted name containing a double-sharp or double-flat.

6. B-double-flat harmonic minor scale descending

For harmonic minor scales, the notes names when descending are just the reverse of the ascending names.

So assuming octave note 8 has been played in the step above, the notes now descend back to the tonic.

7. B-double-flat harmonic minor scale degrees

Scale degree names 1,2,3,4,5,6, and 8 below are always the same for all major and minor scales (ie. 1st note is always tonic, 2nd is supertonic etc.) , but obviously the note names will be different for each scale / key combination.

In the harmonic minor scale, the 7th note is called the leading note or leading tone because the sound of the 7th note feels like it wants to resolve and finish at the octave note, when all scale notes are played in sequence.

It does this because in this scale, the 7th note is only 1 half-tone / semitone away from the 8th note - the octave note. The Bbb major scale and Bbb melodic minor scale scales share the same property - they both have only one half-tone / semitone between the 7th and 8th notes.

In contrast, the Bbb natural minor scale has a whole tone (two half-tones / semitones, two notes on the piano keyboard) between the 7th and 8th notes, and the 7th note does not lean towards the 8th note in the same way. In this case, the 7th note is called the subtonic.

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