• Root motion is the movement from one chord's root to another chord's root.
• To demonstrate root motion, we will use a I and a vi chord in C Major.
• The root of the I chord (a C major triad) is C.
• The root of the vi chord (an A minor triad) is A.
• Therefore, the root motion between I and vi (C to A) is down a third.
• Due to interval inversion, the root motion could also be classified as up a sixth.
• Let's try another example: a IV chord going to V.
• The root of the first chord (an F major triad) is F.
• The root of the second chord (a G major triad) is G.
• Therefore, the root motion of these two chords is up a second or down a seventh.
• Let's try another example: a I chord in first inversion going to a root position V.
• The root of the first chord (an C major triad) is C. Since the chord is inverted, the root is not the lowest note.
• The root of the second chord is G.
• The root motion of these two chords is down a fourth or up a fifth.
• A circle progression occurs when root motion is equal to up a fourth or down a fifth.
• Both I->IV and ii->V are circle progressions.
• iii->vi and IV->viio are also circle progressions.
• Let's work out all possible circle progressions for a major scale, starting at I.
• I progresses to IV.
• IV progresses to viio.
• viio progresses to iii.
• iii progresses to vi.
• vi progresses to ii.
• ii progresses to V.
• V progresses to I.
• The major scale circle progressions are: I->IV->viio->iii->vi->ii->V->I.
• Next, we will work out all possible circle progressions for a minor scale.
• i progresses to iv.
• iv progresses to VII (not viio).
• VII progresses to III.
• III progresses to VI.
• VI progresses to iio.
• iio progresses to V (not v).
• V progresses to i.
• The minor scale circle progressions are: i->iv->VII->III->VI->iio->V->i.
• This chart displays the circle progressions for both major and minor scales.