The KeyMusician Blues
This past month, I had an occasion to improvise an additional part with the background music used by a singing group. One of their pieces had a 'blues' sound to it, and in improvising with it, I suddenly found I had to manually play accidentals (flats in this case) for half of the notes! Because of this, I quickly 'retreated' to harmonizing notes in the bass, corresponding to the chords, which was much less than I would normally do in improvising a part.
The reason this happened, is that a 'blues' piece is not based on a diatonic (major/minor) scale. It is based on a blues scale.
This difference is even more striking when you find that the blues scale has only 6 notes, where a diatonic scale has 7.
Where the KeyMusician Keyboard handles the black-key/white-key decisions for you, it makes things very easy. But when you play in a scale where half of the notes are guaranteed to be manually-played accidentals, it makes things difficult. You might call it The KeyMusician Blues...
I've got the KeyMusician Blues!
Fortunately, there is a simple solution to make it much easier to play, only requiring accidentals for one of the 6 notes of the scale.
For the solution, we first need to look at the blues scale.
Description of the Blues scale
The Blues scale consists of 6 different notes (unlike
a major or minor scale, which has 7 notes).
They are the 5 notes of the minor pentatonic scale, plus one additional note.
The note added is the diminished
5th (flatted-5th) measured from the scale tonic (1st
note of the scale).
adding to the C minor pentatonic scale: C, Eb, F, G, Bb, C
the diminished 5th - Gb
produces the C Blues scale: C, Eb, F, Gb, G, Bb, C
(Note that in the scales shown here, the beginning note (the C) is repeated at the end of the scale, but it does not count as a unique note of the scale.)
In relation to the Major scale, the notes of the Blues scale are: 1st, flatted-3rd, 4th, flatted-5th, 5th, flatted-7th, 1st.
The flatted-3rd, flatted-5th and flatted-7th notes of the scale (for the C Blues scale: Eb, Gb and Bb) are the so called blue notes of the scale.
The table below contains the Blues Scales in all 12 keys listed in Circle-of-Fifths order.
You can't handle the fourth note of the blues scale using a key-signature.
For example, in the C blues scale, the G-flat can't be done as an F-sharp because the F-natural is a part of the scale. Similarly, the G-flat can't be done with the key-signature because the G-natural is required.
This note must be played (manually) as an accidental (a note not in the key-signature), no matter what key-signature is used.
The key-signature is normally based on the first note of the scale. But the key-signature that goes with the first note of the scale will require you to manually play accidentals for 3 of the 6 notes of the scale! If you add two flats to the key-signature, only one of the 6 notes of the scale has to be played as a manual accidental.
Table 1 – Blues Scales (all)
* Key-signatures with 7 flats (or 7 sharps) are not currently supported by the KeyMusician Keyboard because you can play the same key-signatures with a lesser number of sharps (or flats).
Note that you can use the key-signatures in the table above to yield the minor pentatonic scale for each starting note, because the 4th note of the blues-scale is eliminated, which also eliminates the need to play any accidentals.
Rule For Calculating The Key-Signature
Take the key-signature that appears in the music, and add two flats to it.
For example, if the key-signature has 1 flat, the blues key-signature has 3 flats.
If the key-signature has sharps, the 2 flats added cancel-out sharps.
For example, if the key-signature has 3 sharps, the blues key-signature has 1 sharp. If the key-signature has 1 sharp, its blues key-signature has 1 flat.
By setting the key-signature using the rules above, you'll only need to play accidentals manually for one of the notes of the blues scale. Since the blues scale contains 6 notes rather than 7, some notes (that you would play in an ordinary scale) will need to be skipped (not used) in playing music based on a blues scale.
By setting the key-signature using the rules above, most of the chords you need will appear in the chords pane. You'll only have to flat (or sharp) one of them. Both modal and standard chords can be used. The root note of the blues key will be the #2 chord (rather than the #1 chord).
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You can get more information about blues scales (and other scales & jazz-related topics) at the link below: