iternabe Found this excellent video that seems to teach what Stephen Ridley claims but in a way that is solid, easy to understand, and practical. It is eye opening to me to see how music theory is to be used in learning real music. His method does not even rely on the player have perfect relative pitch. What it does require, as he said, to know your scale and chord progression inside and out, which would obviously takes lots and lots of practice.
I watched the video. He does make a good summary of the main principles. The "in minutes" has the qualifier that you can do it in minutes if you have some prerequisite skills in place (as you write that he says).
I took a 6-week Coursera course with an excellent Berkley teacher. In regard to the tonal center, it is true that very often a song will end on the Tonic (tonal center). The Berkley teacher had us listen for the tonal center without mentioning that last note. He had us listen for the note that the music seemed to gravitate toward and settle on. This was the first step.
We were then given an assignment: Listen to music out there, and find 5 which are in the key of C. This wasn't as easy as it may seem. First you had to fixate on what "C" sounds like. I kept blowing into my tenor recorder. The way Coursera works, you grade each other's work and try to grade at least 4 of them - criteria being, "Did they identify music in C". I did a bunch, so as to learn - quite a few identified music that was in G, as being in C. The reason is that the Dominant chord (V) is also very prominent.
We were then given only the I, IV and V for a 12 bar blues. The last assignment was to create two short riffs (call-answer) over a prerecorded bassline, in the key of Cm (I think). The riff was just a handful of notes that fit in with the chord, and then you played the same thing fitting into the next chord.
What we worked with was limited. No series of chords: no going into other keys. That's why I'm thinking that the video you featured (not the Ridley one ofc) is a good overview.
In the overview video, I actually identified the wrong note as the center, because the vi chord is so prominent. I'm weak in this area. In the Berkley course I was shocked that I got tonal centers wrong in the examples, because my background is Common Practice music, a steady diet of sonatinas since that's all I had, and listening via solfege. I identify melody before anything else. I don't have an ear for chords. I did all three levels or RCM rudiments and passed the middle exam with a grade of 99.95% - but there's a TON I'm weak in. I was warned some years ago that the traditional path I was on would put music and me "in a box". These days I see both the box aspects, and the usefulness. I took the Berkley course in order to round things out a bit.