Building Blocks: Relative Keys

 

    If this is your first time here I recommend going here to follow the lessons up to this point.  In the last lesson we explored major keys and their relationship in 5ths.  We learned that each major scale has it's own key signature, each with different amounts of sharps and flats.  Here we will learn that each key signature can actually represent two keys: one major key and one minor key.  

    In the lesson on natural minor scales, we learned that the A Minor scale uses the plain notes of the musical alphabet, just like the C Major scale.  The only difference is that the A Minor scale starts on A, not C:

A  B  C  D  E  F  G  A

     Remember C Major is:

C  D  E  F  G  A  B  C

    So we can see that both A Minor and C Major share the same notes, the only difference being the starting note for each scale.  Remember that what makes a major scale "major" is the pattern of whole and half-steps (WWHWWWH) starting from the tonic note, in this case "C".  One way we could think about A Minor is that it is the same as the C Major scale, but starting on the note A.  Although this is absolutely correct, this is not typically the preferred way to think about it because it doesn't reflect the way it's used in actual music.  

    By writing out the C Major scale starting on A, we've changed where the half and whole-steps are in relation to the tonic.  The half-steps are still between B and C, and E and F, but those pairs of notes are no longer the 3rd and 4th notes and 7th and 8th notes of the scale.  Now they are between the 2nd and 3rd notes and the 5th and 6th notes of the scale, giving us the pattern WHWWHWW, which we learned is the pattern that makes a minor scale.  

    Even though the C Major scale and the A Minor scale share the same notes, it's not particularly helpful to think of them as two different versions of the same scale, because they each have a different tonic.  Remember that "tonal" music is based on the idea of having a central key, where one note (or chord) is "home" and sounds like the "goal" or "resolution" of the melody or chord progression.  This is the whole point of having "keys".  

    Since minor scales work on the same aspects as major scales (there's only one of each letter name, no two minor scales are the same, there's a step pattern that makes them minor and not anything else, etc), they are related by 5ths in the same way major scales are.  Because of this, minor scales fit into the circle of 5ths in the exact same way major scales do, and their flats and sharps are added in the same way as major scales.  Just like major scales, minor scales can have up to seven flats or seven sharps, and there's one minor scale (A Minor)n that has no flats or sharps.

    C Major and A Minor are "related" because they share the same notes.  Because of this we call them Relative Keys.  A Minor is the relative minor of C Major.  C Major is the relative major of A Minor.  Since C Major and A Minor share the same notes, that also means that they share the same key signature (no flats or sharps).  

    If we think back to the circle of 5ths, we see that G Major is the next scale after C Major, because it starts on the 5th note from C:

C  D  E  F  G  A  B  C

    If we arrange the notes starting from G we get:

G  A  B  C  D  E  F  G

    Remember that going up a 5th means we add a sharp, and the first sharp we add is F# because it's the first sharp in the order of sharps (remember "Funky Chickens Get Down At Every Barnyard"), which gives us the G Major scale:

G  A  B  C  D  E  F#  G 

    Now let's do the same thing with the A Minor scale.  The 5th note of the A Minor scale is E:

A  B  C  D  E  F  G  A

    If we arrange the notes starting from E we get:

E  F  G  A  B  C  D  E

    Going up a 5th means adding a sharp, and the first sharp in the order of sharps is F#, which gives us the E Minor scale:

E  F#  G  A  B  C  D  E

    Remember A Minor and C Major share the same key signature (no sharps or flats) because they are "relative" to each other, meaning they share the same notes.  Here we can see that both G Major and E Minor share the same notes, meaning they are "relative" to each other and therefore share the same key signature (one sharp).  It just so happens that ALL minor keys have a relative major key and vice versa, so any one key signature can actually represent two keys!

    An easy way to find the relative minor scale of a major scale is to find the 6th note of the major scale.  Remember that A Minor is the relative minor of C Major.  The note "A" happens to be the 6th note of the C Major scale:

C  D  E  F  G  A  B  C

    A is the 6th note of C Major, and is also the tonic of the relative minor scale of C Major.  We also just learned that E Minor is is the relative minor scale of G Major.  Take a look at the 6th note of G Major:

G  A  B  C  D  E  F#  G 

   We can see here that E is the 6th note of G Major, so it holds true that the 6th note of any major scale is also the tonic note of its relative minor scale.

    This works the other way too.  The tonic of a relative major scale will always be the 3rd note of a minor scale.  See that C is the 3rd note of A Minor:

A  B  C  D  E  F  G  A

    Now see that G is the 3rd note of E Minor:

E  F#  G  A  B  C  D  E

    So, starting with a major scale all we need to do to find its relative minor is find the 6th note, and starting with a minor scale we just need to find the 3rd note to find its relative major.

<  The Circle of 5ths

 

If you have any questions post them in the comments below!