[drewhk]

It is not so clear-cut though. There is a hierarchy here that the article misses a bit I think. There will be participants of various awareness level:

1. Members of the audience that do not notice anything at all 2. Members of the audience that only notice it subconsciously, affecting some overall feeling of quality (an analogy would be typography which operates mostly in this realm) 3. Members of the audience that consciously notice that something is off, somewhere 4. The conductor that exactly knows that the piano is off 5. The tuner that exactly knows what and where is wrong with the piano