The Flat Five Subs

home

The flat five substitution is probably the coolest thing you'll ever learn to do with a chord without having to commit heavy duty practice hours to perfect. Before getting into the theory, accept these two ideas as true: 1) when a chord is being used to create tension, it's okay (cool, in fact) to increase the tension. Put simply. As long as the next chord resolves the tension, it's okay to play wrong notes. This occurs every time you play a V chord and follow it with the I chord. G7 to Cmajor is an example of this. 2) The strongest movement between notes or chords is a half step. This means that moving from C# (note or chord) down a half step to C will have a stronger impact in the listener than, say, G to C.

The flat 5 sub effects both of these concepts. Take a look at the G7 chord. G7 is made up of the notes G, B, D and F. If G7 is followed by C (maj. or min.), you can add just about any note to the G7 chord. Any dissonance created by the extra notes will enhance tensions and result in a stronger resolution to C. We call this "altered" dominance. Th flat 5 sub adds alterations to a dominant chord without effecting the notes that define the chord as dominant.

This is the chord G7 broken into it's individual notes and intervals.

Find the flat 5 sub by counting up to the flatted fifth from G and building a dominant chord from that note.

The chord which substitutes G7 is Db7. We could stop right here and make effective use of this type of substition chord by saying that, anytime G7 is followed by C, it's okay to substitute Db7. But why? On the surface Db7 looks nothing like G7. To understand why this works, it's necessary to compare the notes in both chords.

Regardless of which chord we use, the function of the G7 chord needs to be maintained. Followed by C, G7 is the V chord making it OK to play dissonant notes in it (idea #1). In the lesson on chord construction, we learned that the 3rd. and 7th. (color tones) define a chord as major, minor or dominant. As long as the 3rd. and 7th. from the G7 chord remain, it doesn't really matter which other notes are played in the chord. As we can see, the D7 chord is the equivelent of G7 (b5 b9).

Finally, we put it all together by using the flat 5 sub in a chord progression. The ideal place to use the flat 5 sub is the ii, V, I chord progression. By replacing G7 with Db7, we have seen that the alterations b5 and b9 occur. In a ii, V, I chord progression, the flat 5 sub occurs directly between the ii and the I chords. This gives us the functionality of the standard ii, V, I but moves in half steps (idea #2).

Since the flat five sub appears a half step up from the I chord, it isn't necessary to do all the calculating to find the chord. This makes using the flat 5 sub very easy once you have worked out the moves.