Excellent article but, for the record and the uninitiated, the ability to read music does NOT automatically exclude a person from playing "fiddle"   The publishers of "fiddle" music and methods would be very unhappy if that were the case.  In addition, reading music is a much faster way to get to playing a piece.

(However, I doubt if a music stand is a welcome accessory at a jam

( True story  .... a small country church had one man who knew all the hymns and he would call out the words for the congregation to sing.  There were no hymnals.  Then they raised the money needed to buy hymnals and this was a disaster.  Nobody could read and "playing by ear" was born!)