Well stated. Especially the last paragraph. Great Movie BTW.

I made my living as a guitar tech for more than a decade. One of the myths concerns adjusting the truss rod. For those of you who do not play, the truss rod controls the amount of relief, or curvature in the fingerboard. The curve is necessary because a string vibrates in an elliptical pattern. If the fingerboard is completely straight and level the strings buzz against the frets. Buzzing is noise and therefore bad. In most cases.

The myth: Never turn the truss rod nut more than one quarter turn per day.

The rationale: It takes time for the neck to acclimate and settle into the new shape.
The answer: Sort of. It can take a day or two for the neck to cooperate. But it is almost always instantaneous and stays that way.

The accepted rationale: The truss rod will break if the nut is turned more than one quarter of a revolution per day.
The real answer: Only if the truss rod nut is at the end of the threads. It will be very tight. If turned it will squeak. Stop! Which can be a problem for people who don’t use hand tools. The fix is to add a washer or two to the end of the rod and continue adjustments. If the neck continues to behave this way, the problem lies elsewhere.

The ridiculous rationale: The neck will explode into a million pieces. Or at least crack.
The answer for ridiculousness: Given that a guitar neck is roughly one half of a baseball bat and the truss rod is a 3/16″ piece of cold steel, the chances of the neck cracking, let alone exploding, are negligible.

Guitar repairmen, builders, and techs turn the truss rod nut until the neck achieves the proper relief. That takes mere seconds. It’s true that sometimes the wood in the neck will return somewhat to the original curvature. That is remedied by making a second adjustment.

Think about it. If the myth were true it would take days, sometimes weeks, to make the very first adjustment when setting up a guitar. Guitar shops all over the planet would be out of business in less than a month if the myth were true. Yet, techs and repairmen spend a lot of time explaining all of this to their clients, many of whom will never believe them. They will continue to believe the misinformation that their buddy told them or they found on the internet. At best, they never trust the repairman after that. At worst, they tell all their friends that the shop is run by hacks and charlatans.

The thing is, people who believe the myth never ask, “Why?”

There is a scene at the end of the movie, The Man Who Shot Liberty Valance in which Ransom Stoddard, played by Jimmy Stuart is being interviewed by some newspaper reporters. He tells the truth. He did not shoot Liberty Vallance. The newspaper reporter replies, “When the facts don’t fit the legend, print the legend.”