What is meant by a pitch raise.

The standard pitch throughout the music industry is A-440. When a piano is properly maintained, this pitch will be maintained. However, when a piano has not been tuned for a year or more, it will have lost pitch and be below standard pitch and will often result in the requirement of more than one tuning to correct it. This/these first tunings are what is called a pitch raise. In fact, a pitch raise is not actually a tuning as its purpose is to raise, or lower pitch and strings are over stretched to ultimately accomplish this. The strings will quickly stretch under the new tension, finding a level. This then requires another tuning, a fine tuning, to correct, leaving the piano stable again.