Explaining the Minor scale system
My guide to the minor scale system: essential features and terms for all musicians
Minor scales are poorly and incompletely explained in my textbooks; fortunately, the excellent teachers at Douglas College and the alternate viewpoint provided by my jammer helped me understand the system. I hope this little guide saves you time and effort.
Any mistakes are solely mine. If you find errors, please let me know about them soonest.
The minor scales system developed haphazardly, so has odd conventions and notation. Fear not, the system is not that hard.
Scales are sets of notes, spaced in a fixed set of pitch intervals, and the set may be different ascending and descending. (Wikipedia: Scales)
A reasonable summary of the minor scales system is in chapter 7, Minor scales and keys (pg. 165) of The Musician's Guide to Fundamentals, Jane Piper Clendinning, et al., W.W. Norton, 2012
in order to understand the minor scales, let’s start with the Major scale, the workhorse of modern music. Each note in a scale has an exact, but pitch-distance relative to companion notes. Musicians are so familiar with the major scale that the notes are simply labelled 1-2-3-4-5-6-7-8, their uneven note-spacing is ignored, and the various scales are usually evaluated in terms of differences from the major scale.
The major scale‘s notes fit well together, for details, see: how the major scale began and works.
[Diagram] Here are the jammer keys and sequence to press [diagram here] to play this scale.
Next, the Parallel key and the Natural Minor scale.
Every major key also has a closely related key, the parallel key, whose notes follow the natural minor scale, with notes 1-2-b3-4-5-b6-b7-8, where the b means “flatten the note by a semi-tone”.
The natural minor scale retains the all-important 1st, 5th, and 8th (root, dominant and octave); and to a lesser degree the 4th and 2nd (sub-dominant and super-tonic) these notes fit together to create the scale’s tonal centre, the tonic. In very early music, this was called Aeolian mode and was perhaps favored because it works well with bells, the common musical instrument of the time. The Aeolian scale’s flattened 3rd, 6th and 7th tune well with the 5th (dominant), 8th (octave) and 2nd (super-tonic). This different tuning makes for a nice, somewhat melancholy variation from the major scale.
The key signature for every parallel key has three flattened notes compared to its companion major scale, that is, the natural minor scale flattens the 3rd, 6th and 7th notes of the major scale, while the tonic remains the same.
For example, A major has 3 sharps, but A minor has 0 flats (3 sharps – 3 flats = 0 flats), G major has 1 sharp, while G minor has 2 flats (1 sharps – 3 flats = 2 flats). Although the scale has 3 flattened notes, again the tonic remains the same.
The pure Natural Minor scale is not used today.
This lovely scale was the rage in early music. However the flattened 7th note of the scale, the b7, is wishy-washy musically speaking, it lacks drive, especially in chords. Composers for the last century or so have favoured stealing the more harmonic 7th note, the leading tone, from the major scale. This change creates the Harmonic Minor scale described below.
Neither is the Melodic Minor scale used.
This scale had a brief century’s vogue four hundred years ago, especially for singers.
It’s a variant on the Natural Minor scale: when going up flatten the third (b3), play the major scale’s 6th and 7th, but when descending play the natural minor’s b7, b6 and b3.
The Harmonic Minor key is the “real” minor key.
Composers like many aspects of the Natural Minor scale, but dislike its minor 7th, because the major 7th, the leading tone, can do cool musical things. So today’s universal, unspoken rule for minor scale notation is:
“Use the key signature for the natural minor scale: flatten the third, sixth, and seventh, but then make it ‘harmonic’ by re-sharpening the seventh.”
Yes, it's confusing, but generally, for anything written in the last century, "minor key X" or just "x minor" means harmonic minor; most or all of the piece’s sevenths have natural signs or sharp signs.
Reading the Score’s Key Signature: deducing the tonal centre and scale.
The key signature of a score tells the piano player which notes to systematically flatten or sharpen, allowing the pianist to play in keys other than C. The details are fiddly and unimportant. The important thing is that a key signature implies two possible keys, with unrelated tonal centres and completely different jammer fingerings; these are called the relative major and relative minor keys.
These two keys have tonal centres a minor third apart and a different scale pattern, despite sharing the same keyboard keys. Knowing the key does guide pianists where to put the hand and fingering. E.g. zero sharps implies the thumb hang out near C for C-major, near A for A minor, and so on.
Deducing the Relative Minor from the Relative Major.
The relative (natural/harmonic) minor scale has a tonal center three semitones, a minor third, lower than the major scale. For example, C has zero flats, so its relative minor A also has zero flats. The textbooks advise reading the Circle of Fifths chart and memorizing the relationships.
Deciding if the piece is the Relative Minor or the Relative Major.
Given two possibilities, which one applies? If you have a standard keyboard, inspect the beginning and end of the piece, the places that establish and conclude the piece’s key and tonal centre. Look in the bass staff at these locations for the relative major and relative minor tonic note. Also look for the signature of a harmonic minor piece, accidentals (flats or sharps) that raise the b7 to scale degree 7.
The jammer has a different way and needs no memorization.
See this following posting: Jammer shortcuts - Identifying the key, the tonal centre (tonic), scale and playing them.
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Next: Jammer vs Piano - Part 8 - Identifying the key, tonal centre & scale (major/minor) on jammers
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