2nd Dominant

Hi,

As some of you already know, the 5th degree in a Major scale family chord is a dominant chord.
I.e. G7 in the Key of C.

Looking at a common chord progression(1 6 2 5) in key of C , the chords are C Am7 Dm7 G7.

Now, playing the same progression, instead of playing the Am7, play a A7 chord.

You will notice that the voicing is even more jazzy, creating a tension.

That is an example of applying the 2nd dominant.

You can try also changing the Dm7 to a D7 chord, but perhaps play a Am7 instead of A7.

Experiment around.

Have fun.