Functioning & Static Dominants
The next few ideas that we are going to be looking at will apply only to functioning dominant chords, so you need to understand clearly what that means.
A functioning V (dominant) chord is one that resolves to it's I chord.
Hopefully you know your diatonic chord sequence (click here if not) and know that the V chord is a dominant 7th chord. It contains a lot of tension (between the 3rd and b7th degrees of the chord) that wants to resolve to the I chord of it's key. Some examples (but you need to know all of them):
G7 (V) -> Cmaj7 (I)
F7 (V) -> BbMaj7 (I)
Luckily there is an easy way to do it on the guitar neck that saves you from having to remember every note in every key (although that is a good idea).
• If the root note of the V7 chord is on the 6th string, the I chord root will be found in the same fret on the 5th string.
• If the root note of the V7 chord is on the 5th string, the I chord root will be found two frets back (toward the nut) on the 6th string.
Easy peasy. Make sure you understand this fully before moving on.