HARMONIC PROGRESSION - The way in which chords are selected to succeed each other in a piece of music.
CIRCLE PROGRESSIONS - Direction and Drive toward a goal - The Tonic!
Descending Fifths - I IV viio iii vi ii V I - moving toward a Perfect Authentic Cadence.
(Reminder: the Viio6 - I can be interchanged with V - I as they share the same pitches...
Ascending Fourths from a Deceptive Cadence - vi ii V I
Ascending Fifths, Ascending Seconds, Ascending Fourths - I IV V I (This progression will switch the circle).
The Music of the Classical Period depended heavily on standard chord progressions for its structure.