09/20/2022
FAQ series 2!
This is another aspect of piano maintenance thats a mystery to most. Its a common procedure that piano technicians do all the time. But, it can be prevented by regularly servicing your piano!
A quick explanation of A440. A440 refers to A4, the first "A" above middle C, being set to a frequency of 440 Hertz. Hertz is a measure of frequency or pitch. By the laws of physics, one can logically assume that if A4 is 440Hz, then A3 is 220HZ, and A5 is 880Hz and so on. So therefore, all the notes within each octave fall within a certain frequency range. If A4 is tuned to 440 then C4 (middle C on a piano) falls at around 261HZ.
Pianos are built to hold stable string tension when A4 and the rest of the piano is tuned to A440. Unfortunately when a piano hasn't been serviced in a year or more, the string tension slips and the piano falls flat. Meaning that A4 is not tuned to A440 anymore. The piano may be in tune with itself, meaning the piano may sound decent by itself. But as soon as you try to play along with a recording or even play with an instrument that is tuned to A440, the notes will not match. Ive seen pianos that have fallen almost a half step flat.
This is where the pitch raise comes in. If I show up to a piano and the starting pitch of A4 is 420Hz, this definitely calls for a pitch raise. I need to get the piano back to A440. So I will do a pitch raise tuning or a "quick pass" tuning. This is a quick tuning to stretch the strings back to A440. Because the strings move so much in this instance, I need to fine tune the piano once more, in the same appointment, to make the piano stable once more at A440. This is why pitch raises can add to the final cost of the tuning. It also takes skill and experience to understand how the strings stretch and where they will naturally land based on how far off the piano is.
Phew! A long winded explanation! Like I said before, you can avoid pitch raises by regularly servicing your piano at least twice a year!