A. Kori Hill
Now I hear you asking: how do you know which minor scale is related to the particular major scale???? What is a relative key versus a parallel key??? And I say: use the rule of thirds, and refer to the tonic!
Relative keys are scales that share the same key signature but have different tonics. You can identify relative scales by using the rule of a minor third (or the rule of a major sixth!). The tonic of a minor scale is going to be a minor third (aka three half steps) below the tonic of its relative major.
So, if you need to find the relative major of E minor, go up three half steps and you’ll arrive in G major! And if you want to find the relative minor of G major, go down three half steps, and you’ll arrive in E minor. Another way you can do it is by going up or down a major sixth from the tonic in question (G to E is a major sixth up; E to G is a major sixth down).
Parallel keys are scales that have the same tonic but different key signatures. So, A minor and A major are parallel keys, but A minor doesn’t have any sharps or flats, and A major has three sharps (F#, C#, G#).
In Western classical music, relative keys are a convenient way to modulate: this is when you move a section of music from one key to another key. But that doesn’t mean you can’t modulate between parallel keys or play around with parallel keys in the same section of a composition!
Take a listen to the opening of Price’s Violin Concerto No. 2. Initially, it sounds like we’re in D minor, but what follows also suggests that we’re maybe in D major. Now, you can say that we’re in a section that’s in D melodic minor because Price plays so much with the raised subdominant and leading tone. But sometimes she also takes us into D flat major (!), which isn’t a parallel or relative key of D major or D minor, strictly speaking.
Now, step away from trying to figure out whether Price is writing in D minor or D major. Listen to the color of the sound: does it seem happy, tense, sad, or settled? Rather than utilize rules of modulation like we study in school, maybe Price is using some different rules, ones that aren’t related to tonal harmony but instead to modal harmony. I’ll be back next time to tell you what modal harmony means because it requires us to take a look at a different way of writing and using scales: modes!
