I play, sing, and perform the way Pete Townsend throws paper wads, intuitively, without benefit of formal musical education. When I speak of this with our sax player, Juilliard trained (the prestigious school of music, New York, USA), referring to areas of my performance that need work, I refer, deferentially, to my lack of education. He responds, "Yes, but you know the songs". And I do, and I can play them, even those that have lots of passing and swing chords, substitutions, inversions, etc. (Guitar)

But fundamentals do count. Where I am deficient, I often lack the language or fundamental understanding to receive communication to correct my deficiency.

There is a point in ensemble playing and the contruction of arrangements where formal training is damn useful.

Or else you may frustrate the hell out of your band.