Watch the Maj. Triad: Alt. Dom. Sound online guitar lesson by Kenny Wessel from Shades of Jazz
In this demo track, I'm going to demonstrate the sound of the E major triad over a G7b913 chord vamp. This is a major triad built a major sixth up from the root of the dominant 7th chord. Listen to the tensions over the G7, in this case, the b9 and the natural 13. Then I will play a G7 arpeggio 1, 3, 5, b7, so we can hear the difference between the consonant chord tones and the more dissonant color tones (b9, 13). As the track progresses, I will demonstrate moving from the arpeggio notes, to the colors, to illustrate the interplay of consonance and dissonance, tension and release. If we are able to control tension and release in our improvisations, we're on our way to really making some music.
Remember, I'm just using simple 135 major triads here, but listen to the alterations we target by playing an E major triad over the G7. Something in music is always something else. A major triad is not just a major triad (in this case it's a G713b9). A hat is not just a hat.