The majority of a piano's range uses notes which are produced by a single hammer hitting not one but three strings simultaneously. We hear it as a single tone.
You would assume that the best quality of sound would be achieved by tuning all three strings to the same exact same frequency -- in unison, but this isn't the case. The three strings are detuned slightly -- this produces a better tone with a longer sustain. The strings are intentionally put out of tune make them sound better.
Poetry with overly meticulous lines falls into a similar pattern -- they need to be more out of whack!