I went straight away to the ET series, specifically ET04 "Dorian Scale", to learn the "one finger, one string" approach as suggested by Prof. Fujita in the day 1 video. From there, I admit, I went down a kind of rat hole. I wanted to learn more about the modes of music and be able to write down the notes of the Dorian Scale with D as the root (D Dorian), as well as with C as the root C Dorian). It turns out there is a neat trick. Some of you will think I need therapy for even mentioning this. But I'm a NERD (Engineer) and I can't help myself. It may be helpful to some of you who are also a bit nerdy. If you use the "Number of Half Steps" method to write the formula for each mode, where 1 = semitone, and 2 = tone, you get the following:
Ionian (Major): 2212221
Dorian: 2122212
Phrygian: 1222122
Lydian: 2221221
Mixolydian: 2212212
Aeolian (Natural Minor): 2122122
Locrian: 1221222
You only need to know the formula for the Ionian Scale: tone tone semitone tone tone tone semitone or 2212221, and the order in which the modes are generally written as they are above. Then, the trick is to take the formula for the Ionian mode (or any other mode) and do what is called in computer hardware design or machine language software design, "a shift left one with end-around carry" to get the formula for the following mode! Isn't that the coolest thing ever?
You shift all the numbers to the left one, and the one that falls off the left end goes around to the right end.
Then you can substitute the "Intervals from the Tonic (Root)" method of representing the intervals: like M2, b3, 4, 5, M6, b7, etc., and write the scale you want to write.
E.g. D Dorian = D E F G A B C D
C Dorian = C D Eb F G A Bb C
I know this level of thinking about it all is contrary to what we all should be doing, which, as professor Fujita says, is don't memorize or think too much, instead learn it as you do it, like driving someplace and not using a map or directions, but just with practice, start to know the way in your bones. I hope this doesn't throw anybody off that process, but that it does help someone a little.
From there, I began practicing the one-finger one-string intervals for D Major and D Dorian, C Major and C Dorian.
Tomorrow, I will continue that with Solfege singing and try to deeply hear the intervals. When I am satisfied with that, I will start working on the three high string triads.