In a rather related, practical application, especially when playing live, and jamming, or in a studio...you might get one of the players who calls out, "go to the 4th"....or the fifth...the second..etc, etc, and you, who may be just sitting in, will know EXACTLY where to go, and know what is related, and so where to go to, or your options....but I'm not sure that people who's musical catalog doesn't go much beyond 'Kumbayah' or Neil Young would care to understand. They probably are not that much interested in music, anyway!

I believe Don would agree.

Regards to All Those Players Who Really Give a Crap About What It Is!

GfS

P.S. Maybe someday when they want to FEEL accomplished, they might even learn the secret chord progression of Carlos Santana....HINT: It's usually TWO chords!