Blues Chords - Dominant 7th
Tue, 11/13/2018 - 12:44
Hi David
Working through Theory 3, Section 3
Im looking at the Domenant 7th Chord and Im confused. I see where we put the flat 7th in place of the F# in the Major. I dont understand where you identify this as a Minor 3rd. Can you explain?
Gary
Hello Gary. The interval between the 5th of the chord and the flat-7ths is a minor third... three half steps.
For definition purposes, a major third is four half steps. A minor third is three half steps. When building a major chord (our I, IV and V chords), from the root of the chord to the 3rd is a major interval... from the 3rd to the 5th is a minor interval. So you can say that a major chord is a stack of three notes, of which from the root to the 3rd is major and from the 3rd to the 5th is minor.
When adding the 7th, the fourth note of the chord, for blues, we want the sound of a minor 3rd (D to F), so G B D F for example instead of G B D F# (F# would be a major 3rd from D, and creates a very different-sounding chord).