So here’s a video lesson about going through our “C” major scale shape using the interval of the 9th. How we find the 9th Interval is by going up 9 scale degrees. What’s interesting about the 9th is it’s the same note as the 2nd degree, just up an octave.
So in this example D is our root note the ninth would be an E (up an octave). We then go to an E and a ninth up from that would be F# (up an octave). etc.
I have a Play Along playlist in which I go through all 7 shapes of our CAGED system through this interval with tab and everything. Don’t forget to try it throughout all sorts of scales as well though (scales playlist annotated in video).