We've all heard a statement similar to the following:
X didn't / doesn't know any music theory and is one of the all time greats
replacing X with a famous guitarist.
Being a novice, I am trying to figure out if this statement can ever make sense:
Take the example of playing and improvising chord progressions (since in my mind this would be more difficult to "fake" than lead guitar): is the above statement really saying that these guitarist essentially make up chords as they go along based upon intuition and ear alone? To me, this would be extraordinarily impressive (of course there are prodigies, but I'm wondering if this is the commonplace explanation for the provided statement).
On the other hand, say they initially learned to play by mimicking the songs and styles of other guitarists. Maybe at that point they built up a lexicon of available chords (and maybe even they can name them) and which sound good together. In my mind, this is, in some sense, knowledge of music theory. Is this what people usually mean when they claim lack of music theory knowledge? Is this not considered knowing (to some degree) music theory?