# B-flat aeolian mode

The Solution below shows the B-flat aeolian mode notes on the piano, treble clef and bass clef.

The Lesson steps then explain how to identify the mode note interval positions, choose note names and scale degree names.

For a quick summary of this topic, have a look at Mode.

 Key C C# Db D D# Eb E E# Fb F F# Gb G G# Ab A A# [Bb] B B# Cb

## Solution - 2 parts

### 1. B-flat aeolian mode

This step shows the ascending B-flat aeolian mode on the piano, treble clef and bass clef. It also shows the scale degree chart for all 8 notes.

The B-flat aeolian mode has 5 flats.

B-flat aeolian mode note names
Note no.Note intervalNote name
1tonicThe 1st note of the B-flat aeolian mode is Bb
2Bb-maj-2ndThe 2nd note of the B-flat aeolian mode is C
3Bb-min-3rdThe 3rd note of the B-flat aeolian mode is Db
4Bb-perf-4thThe 4th note of the B-flat aeolian mode is Eb
5Bb-perf-5thThe 5th note of the B-flat aeolian mode is F
6Bb-min-6thThe 6th note of the B-flat aeolian mode is Gb
7Bb-min-7thThe 7th note of the B-flat aeolian mode is Ab
8Bb-perf-8thThe 8th note of the B-flat aeolian mode is Bb

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.

B-flat aeolian mode degrees
Note no.Degree name
1Bb is the tonic of the B-flat aeolian mode
2C is the supertonic of the B-flat aeolian mode
3Db is the mediant of the B-flat aeolian mode
4Eb is the subdominant of the B-flat aeolian mode
5F is the dominant of the B-flat aeolian mode
6Gb is the submediant of the B-flat aeolian mode
7Ab is the subtonic of the B-flat aeolian mode
8Bb is the octave of the B-flat aeolian mode

### 2. B-flat aeolian mode descending

This step shows the descending B-flat aeolian mode on the piano, treble clef and bass clef.
 No. Note 1 2 3 4 5 6 7 Ab Gb F Eb Db C Bb

## Lesson steps

### 1. Piano key note names

This step shows the white and black note names on a piano keyboard so that the note names are familiar for later steps, and to show that the note names start repeating themselves after 12 notes.

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-flat aeolian mode tonic note and one octave of notes

This step shows an octave of notes in the B-flat aeolian mode to identify the start and end notes of the mode.

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

The B-flat aeolian mode starts on note B-flat.

Since this mode begins with note Bb, it is certain that notes 1 and 13 will be used in this mode.

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

 No. Note 1 2 3 4 5 6 7 8 9 10 11 12 13 Bb B C C# / Db D D# / Eb E F F# / Gb G G# / Ab A Bb

### 3. B-flat aeolian mode note interval positions

This step applies the B-flat aeolian mode note positions to so that the correct piano keys and note pitches can be identified.

In their simplest / untransposed form, modes do not contain any sharp or flat notes.

This can be seen by looking at the Mode table showing all mode names with only white / natural notes used.

The aeolian mode uses the  W-H-W-W-H-W-W  note counting rule to identify the note positions of 7 natural white notes starting from note A.

The B-flat aeolian mode re-uses this mode counting pattern, but starts from note Bb instead.

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.

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

Again, the final 8th note is the octave note, having the same name as the tonic note.
 No. Note 1 2 3 4 5 6 7 8 Bb C C# / Db D# / Eb F F# / Gb G# / Ab Bb

One or more note in this mode has a sharp or flat, which means that this mode has been transposed to another key.

### 4. B-flat aeolian mode notes

This step tries to assign note names to the piano keys identified in the previous step, so that they can be written on a note staff in the Solution section.

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

The rule ensures that every position of a staff is used once and once only - whether that position be a note in a space, or a note on a line.

This is needed to ensure that when it comes to writing the mode notes on a musical staff (eg. a treble or bass 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).

Applying the rule below ensures that when accidental adjustment symbols are added next to staff notes as part of composing music based on that mode, these accidentals will indicate that the adjusted note is not in that mode.

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 mode 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 mode note name.

If the natural white note can be found in the mode note, the mode 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.

B-flat aeolian mode
No.WhiteMode NoteMatch?
1BBbBb
2CCC
3DC# / DbDb
4ED# / EbEb
5FFF
6GF# / GbGb
7AG# / AbAb
8BBbBb

For this mode, all notes have a match, and so the Match? column shows the mode note names.

### 5. B-flat aeolian mode descending

This step shows the notes when descending the B-flat aeolian mode, going from the highest note sound back to the starting note.

For all modes, 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.

 No. Note 1 2 3 4 5 6 7 Ab Gb F Eb Db C Bb

### 6. B-flat aeolian mode degrees

This step shows the B-flat scale degrees - Tonic, supertonic, mediant, subdominant, dominant, submediant, etc.
Each of the notes in this mode has a degree name, which describes the relationship of that note to the tonic(1st) note.

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

In this mode, the 7th note is called the subtonic, and it has a whole tone (two semi-tones, two notes on the piano keyboard) between the 7th and 8th notes.

In contrast, for example, the lydian mode has only one semitone / half-tone separating the 7th and 8th notes, and in this case the Seventh note is called the leading note or leading tone, as the 7th note feels like it wants to resolve and finish at the octave note, when all mode notes are played in sequence.

The modes that have a subtonic as the 7th note are dorian mode, phrygian mode, mixolydian mode, aeolian mode and the locrian mode.

B-flat aeolian mode degrees
Note no.Degree name
1Bb is the tonic of the B-flat aeolian mode
2C is the supertonic of the B-flat aeolian mode
3Db is the mediant of the B-flat aeolian mode
4Eb is the subdominant of the B-flat aeolian mode
5F is the dominant of the B-flat aeolian mode
6Gb is the submediant of the B-flat aeolian mode
7Ab is the subtonic of the B-flat aeolian mode
8Bb is the octave of the B-flat aeolian mode