It is imperative for anyone's musical development that your instrument be tuned to the correct pitch of A = 440 Hz.
A child should learn on a correctly tuned piano at
A =440 in order to have a good musical ear. Also, your piano should always have all of its strings at the correct tension otherwise it will deteriorate. That is why it is important that the extreme treble or bass sections should be in tune even if you do not use them so much as the middle part of the keyboard.
Even if you do not play your piano, it will go out of tune because of the 40,000 pounds of tension of its frame.
230 strings distributing 130 to 300 pounds of tension each produce a force strong enough to lift a house from its foundations!
Everytime there is a change in humidity or temperature, the pitch will change, causing numerous problems in its regulation.
The 12,000 parts will absorb moisture, including its most important and expensive one, the soundboard. As it collects humidity, the wood will expand and swell, tightening the strings which will raise pitch, usually in Summer.
On the contrary, in Winter, the wood will shrink, even crack, which will cause the strings to loosen and the pitch to decrease.
All those problems will not share evenly in the piano, making it even worse.
Humidity also causes strings to rust and at a certain point will require changing those strings or they will break and lose their elasticity.
It is possible to fine tune a piano which keeps its relative humidity level at 42 %, but impossible to tune a piano with a cracked bridge, a cracked soundboard or whose pitch fluctuates several times a year.
A new piano will need more frequent tunings when new. it is because a new string has some elasticity, and it will stretch for a certain period of time. Then a string will not stay in pitch, but will rather stretch and drop in pitch in a matter of hours. Then, the more you tune a piano during its first year, the more stable it will stay later.
Properly and regularly taken care of by a professional piano technician, a piano can be a good musical instrument for more than a generation.
PREVENTION is the best way to take care of a piano.
Never changing the oil in a car means having to change the engine one day.
Driving a car that would not be in perfect condition would be unsatisfactory (and dangerous!)
Learning to play the piano is challenging.
I know by experience that it is much more challenging to play on an unregulated and out of tune piano. (As I have had to accompany students in school competitions on very poorly kept pianos).
A well-maintained piano is rewarding and easier to play for the pianist, affordable for the owner and will play beautiful music for a long time.