I hoped this topic would draw some interesting remarks. I has.
Without boring us with my personal history, when I approached
music theory, I was informed piano playing takes one of at least
two tracks -- chord based and for lack of a better term, hymnbook
approach. I had to chuckle at Mario's comment. His wife, apparently, is classically trained.
Now, we find the country and blues players use chord based. Chord mastery permits playing in any key. Even as far as melodies go, the pianist has a good feel for 1-3b-3-4-5-7 and 7b. That's a pretty good start, if you ask me; though I don't know how I could get along without the 2 and 6.
The pianist is likely thinkng in terms of scale degrees instead of letters. How many great six string guitar players use a position based system with barres and triads? A lot.
Here is a site that was recently posted and demonstrates the chord approach.
https://martingureasko.com/
https://www.youtube.com/user/Martingur1
Over the years, I have concluded that church pianists built themselves a certain job security by learning to play the major keys by sight. As tastes have changed, many find themselves at a loss to play with a bass player. That's been the job of the left fingers. Martin Gureasko mentions several times how important it has been for him, a Nashville professional, to not step on the bass and rhythm lines,. just because he can.
I learned the guitar neck by playing single note lead sheets
with backing tracks.

Last edited by edshaw; 05/29/20 03:51 PM.
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