The sound of using triad chords within the blues structure is definitely one which is not only unique, but a lot of fun to jam out on. For example, we can easily achieve blues harmony if we raise both the 3rd and the 5th degrees of a Major triad by way of a Minor 3rd interval. By doing this simple shift of the notes found in the major triad, we can create the sound of a Dominant Seventh harmony, (the primary color of Blues Harmony).
This Dominant (Blues) harmony occurs when the prior 3rd degree note of a major triad travels up a minor 3rd and becomes the 5th of the Dominant chord. And, what was the 5th of the major triad becomes the b7 degree of our Dominant chord when it is moved up a minor 3rd.
In the video, I don't get too hung-up on all of the music theory details. Instead, I zoom in on the neck and walk through a 12-bar blues that I created, which not only applies the dominant chord triad concept I just mentioned, but also a few other triad chord concepts as well. On screen TAB is included for the entire example of my blues jam. Watch the video to learn more: