Hope this is the right place to ask. Hi.
Could the 6th intervals be built of any of the notes in the scale? In this example (key of E) we build 6ths from the 3rd (G#) in the scale and the 1st (E) to create a chord tone. In another example could we start on, say, the 2nd (F#) and the 7th D (#) and build 6th of that up the scale? I am guessing Justin has done it this way because of the ease of playing the two notes in Harmonic Intervals. Thanks, just trying to get my head around the theory behind it, it may not be relevant.