Parallel scales are scales that share the same root note, or tonic. It’s easy to confuse them with relative scales, which share all the same notes, but have a different tonic note. In this lesson we’ll take a look at what parallel scales are, how to figure out the notes of the parallel scale, and common uses for the scales.
What are parallel scales?
As stated above, parallel scales are scales that share the same root note. For instance, if we consider the C major scale, its parallel minor scale would be C minor. This is because they both share the same tonic note, C.
Likewise, if we take the A minor scale, its parallel major scale would be A major. They both share the A note as the tonic.
What’s the difference between relative and parallel scales?
Relative scales are scales that contain the same notes. However, they do not share the same tonic, so they are not parallel scales. An example would be G major and E minor.
The relative minor of a major scale can be found on the 6th degree of the major scale, while the relative major of a minor scale can be found on the 3rd degree of the minor scale.
Finding the parallel scale
To find the parallel scale, we need to consider the formulas that make up a given scale. In music, the major scale is used as the reference point for other scale formulas. So let’s use the major scale as our starting point and C major for our example.
The major scale consists of the following intervals:
Root – Major 2nd – Major 3rd – Perfect 4th – Perfect 5th – Major 6th – Major 7th
In C major, this gives us the following notes:
C D E F G A B
Starting here, let’s find three parallel minor scales: natural minor, harmonic minor, melodic minor.
Parallel minor scale (natural)
The natural minor scale follows the scale formula of Root – Major 2nd – Minor 3rd – Perfect 4th – Perfect 5th – Minor 6th – Minor 7th
To get the minor scale formula from the major scale, we just need to flatten the 3rd, 6th, and 7th scale degrees. If we take a look back at the C major scale, we see the E, A, and B notes are the 3rd, 6th, and 7th scale degrees respectively.
If we flatten each of these notes, we get the following for the C minor scale: C – D – E♭ – F – G – A♭ – B♭
|C Natural Minor||C||D||E♭||F||G||A♭||B♭|
Parallel harmonic minor scale
The harmonic minor scale formula differs from the natural minor in that it has a raised 7th degree:
Root – Major 2nd – Minor 3rd – Perfect 4th – Perfect 5th – Minor 6th – Major 7th
To find the parallel harmonic minor scale for C major, we need to flatten only the 3rd and 6th scale degrees.
|C Harmonic Minor||C||D||E♭||F||G||A♭||B|
Parallel melodic minor scale
The melodic minor scale is a bit more interesting in that the scale has a different set of intervals when ascending than it does when descending.
When played ascending, the interval structure is Root – Major 2nd – Minor 3rd – Perfect 4th – Perfect 5th – Major 6th – Major 7th. This differs from the major scale only at the 3rd scale degree.
Using our example in C, to get the ascending parallel melodic minor scale we just need to flatten the 3rd of the major scale.
|C Ascending Melodic Minor||C||D||E♭||F||G||A||B|
When played descending, the melodic minor consists of the following intervals: Root – Major 2nd – Minor 3rd – Perfect 4th – Perfect 5th – Minor 6th – Minor 7th
Notice, descending the melodic minor scale is exactly the same as the natural minor scale. To get the parallel descending melodic minor scale, we need to flatten the 3rd, 6th, and 7th scale degrees.
|C Descending Melodic Minor||C||D||E♭||F||G||A♭||B♭|
Common uses for parallel scales
Two of the most common uses we see for parallel scales are key changes and chord borrowing.
One use of parallel scales is to introduce a key modulation in a song. This is where the song starts in one key, then at some point moves into a different key. We see this quite often with relative keys where a song will start off in the major key, then switch to the relative minor.
It’s also common that a song may start off in major key and modulate to its parallel minor.
One of the more popular examples would be “While My Guitar Gently Weeps” by The Beatles. The song opens in A minor for the verse, then switches to A major over the chorus.
Give it a listen and see if you can hear the key change when it goes into the chorus.
While My Guitar Gently Weeps – The Beatles
Perhaps the most common use for parallel scales is borrowed chords. Borrowed chords are when chords in a chord progression step outside of the diatonic chords to include chords from the parallel scale. With borrowed chords, you can essentially take any chord from the parallel scale and use it in the progression.
For example, if we look at “Paradise City” by Guns N’ Roses, the intro/chorus use a G, C, F chord progression. In the key of G, there is no F major chord. However, if we look to the parallel minor scale we see that the 7th chord in the key of G minor is the F major chord. In this instance, the F major chord is a borrowed chord from the parallel minor scale.
To summarize, parallel scales are scales that share the same tonic note. While used for key modulation, the most common use is borrowed chords. A chord progression can use any chord from the parallel scale in place of, or in addition to, the diatonic chords for the given key.
Cheat Sheet: Parallel Scales
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