Piano tuning involves adjusting all 225 strings to the proper tension so that the standard concert pitch throughout the piano is achieved. All instruments follow this same principle so they can be played together. The piano tuning procedure needs to be performed on a regular basis to insure this pitch level of A440 is maintained properly. Most notes on pianos have double or triple strings tuned in unison to allow for more volume, depth, better tone quality, and musical dynamics. It only takes a few unisons to be off slightly in a piano to make it sound bad in any key.
How often piano tuners in Minneapolis/St. Paul areas recommend service may differ from other parts of the country due to extreme weather conditions. Other factors that can affect piano tuning stability and maintenenace needs are the piano brand, model, size, age, condition, location, humidity control
, usage, the player, and kind of music played.
Piano tuning should be done on all pianos at least once a year whether the instrument is played or not. String tension of several tons 24/7 causes strings to stretch, which affects pitch. In addition, humidity and temperature changes cause piano components to swell and shrink contributing further to tuning instability. While once a year is a minimum service requirement for a piano regardless of circumstances, most pianos require a more regular and consistent service schedule of twice to several times per year.