A little bit of news about the mediant and sub-mediant chords. Check in your textbook for more.

• These two chords are almost always used in root position.
• Their normal use in chord progressions can be traced to the following root movements:

  Circle of 5ths

  

  Down 3rds

  

  Up 2nds

  

Therefore, vi is usually preceded by iii, I, or V and followed by ii or IV.

iii is usually preceded by I and followed by vi or IV.

Memorize these factoids about these chords and don't use them inappropriately! In other words, if you find yourself on a iii chord, don't go next to a ii or V and don't put this chord in an inversion. Chord "order" or "syntax" is the big issue here, so be careful and think through what you're doing.

NEW CADENCE!

Sometimes, the V chord will resolve to a vi chord instead of the usual I chord. This trickery and chicanery is called a deceptive cadence. They're really nice.