Extended chords add other notes from the scale to the existing root-3rd-5th ... This is our altered note. The E7(#9) is a very well-known chord, but it’s interesting to look at it from this ...
The reason for this is because the E7 features a G# note ... I would urge you to explore the harmonic minor scale across the entire guitar neck using the CAGED system. The good news is that ...