Common Practice Progressions and Composition

Much of what we study are rules based on the common practice of composers throughout the centuries. If a musical trend becomes noticeable, it often transformed into a "Common Practice Rule." These rules are the basis for much of music theory.
When we start to look at harmonic function (chords and their use), we will notice patterns of chord use that appear over and over again in all styles of music.

The "Common Practice" chart of chord progressions is often represented like this:

This chart represents chord progression tendencies.

You might read this chart as, "A I chord can go anywhere, but a iii chord generally moves to a vi which generally moves to either a ii or IV which very often leads to a V or a viio which might move to a iii but more often moves to a I."

A general rule is that IV chords (we often call these subdominants or pre dominants) like to move to a V chord. They really like it. They do it all the time. Because a ii chord shares two common tones with a IV chord, they are often interchanged because they have a similar sound. Likewise, The V chord wants very badly to move to a I chord which you will hear when you start building progressions. The V chord contains the 7th note of the scale (we call this the leading tone) and it is drawn like a moth to the flame to the I. The viio chord has two notes in common with the V chord and that is why we sometimes will use them interchangeably (though not without some considerations that we will get to later).

Of course if all composition simply followed this chart there would not be much innovation and variety in music. This is a guideline that demonstrates tendencies that occur often in music.

Here is a video that was shared with from Mr. Eschelbacher me which takes an example of a common chord progression (one that fits the above chart quite nicely) and demonstrates how it gets used all the time...



His "Ice Cream Changes" are the chord progression I-vi-IV-V-I
Check out how that conveniently fits our common chord chart...

**Your challenge is to create two (2) songs in Garageband. One that follows the rules of common chord progressions (chart above) and one that tries to break those rules whenever possible. What do you think about the results?**