Today, many older pianos exist in various stages of wear. Because this happens so gradually, this wear often goes unnoticed, leaving many pianos operating far below their potential. In extreme cases, some older pianos are simply left unplayed because of their poor condition.
This is where the piano will need to be restored, to bring it back to its original condition or as near as possible.
For an explanation on the type of repairs available, please see piano repairs.