“Costly mistakes” is a term I used to hear much more frequently in the past. Not that it has disappeared from use, but it doesn’t seem nearly so prevalent as it once was.
I’ve been working on a new piece for which I can’t use notation software: the whole thing is going to have to be written out by hand. Drafting the score has made me more aware of how easy it has become to pay less than complete attention to what we are doing in so many of our daily tasks, because so many of our mistakes are instantly correctible. I type these words at lightning speed, with my mind flying ahead of my fingers, knowing that any typos are easily undone. In the same way, I enter music in Finale very quickly and with little fuss, knowing that any mistake I made will be caught later and quickly adjusted.
How different it is to be writing a score by hand! If you leave out a measure and don’t discover your mistake until ten pages later, those last ten pages are going in the recycling. Hours of work gone to waste.
To guard against these little tragedies, one has to exercise a focus-on-task mentality that is a little more severe than normal. Which brings me to my wondering: in giving us an unprecedented ability to correct our mistakes, our technology seems to allow us greater freedom to let our minds wander, which is a good thing, but it has also gotten us out of the habit of concentrating, which is not so hot.
Or, to put it another way: we used to have to waste an awful lot of brain power on measly little tasks, but we were more accustomed to concentrating on every measly little task, which meant that our powers of concentration were well rehearsed. As a result, the ability to concentrate was more readily available to us.
Mistakes are less costly now, and precision is far more dear.