Why do I need a pitch raise?
When a piano has fallen too far below A-440 pitch it will require a pitch raise to bring it up to pitch and equalize the tension on the whole piano. A fine tuning may then be done with a much better outcome and will last much longer.
Why keep a piano tuned?
Upright, grand, and console pianos are strung at a tension of about 40,000 pounds, thats 20 tons! That's why it is very important to keep a piano tuned. If the tension is allowed to drop the whole piano is affected. Pianos are tuned to the standard A-440 pitch unless otherwise requested or if the piano will not hold that pitch (which may be the case with some very old pianos).
Your Piano is made up of approximately 14,000 parts that must all work together properly to produce the sound that it was designed to make. Over time and with use parts will wear, break and move out of adjustment. When you have your piano tuned the qualified technician should also perform an inspection of your piano and inform you of any repairs that it needs to keep it working properly and to provide you with the best performance and sound that your piano was meant to give you.
What is a pitch raise?
When you pull a piece of string very tight and come back a few minutes later you will notice that it is sagging, because it has stretched. A piano string is just a piece of wire under tension, which acts just like the piece of string. If the piano wire that is too far below pitch is tuned to the proper pitch, by the time the tuner walks out the door the string has stretched and is still below pitch, just not as far. When a pitch raise is done, the string is actually tuned ABOVE pitch so that when it stretches it will fall to the proper pitch.