Pitch Raise and Piano Tuning: What's the Difference?

In short, a pitch raise is basically a pre-tuning: it gets a piano close enough to the right pitch so that it can be fine tuned accurately. Seasonal changes in temperature and humidity cause the wood parts to swell and contract, putting the piano out of tune. If a piano has not been tuned or serviced for several years, it will likely be far enough flat that it requires a pitch raise before the tuning.

Now, you might be wondering, "What's the difference between 'at pitch' and 'in tune'? Aren't those the same thing?"

Well, it does sound like the same thing to most non-piano technicians. If a piano is at pitch, the strings are vibrating close to a specific frequency (A440 is typically standard pitch). This is important for developing a consistent sense of pitch and singing or playing instruments in the correct key. It also allows you to play other instruments along with the piano, or tune them to the piano. Further, when a piano is at pitch, the tension of the strings apply the proper amount of tension to the interior components of the piano, including the bridges, soundboard, cast iron plate, and pinblock.

When a piano is in tune, each of the strings vibrates in harmony with the other strings in the piano, causing the entire piano to ring out beautifully! (Of course, this also varies depending on the quality of the piano.) On an in-tune piano, you can play a single note or an octave and you'll hear hardly any "waviness" in the sound of the notes. This makes the piano much more satisfying to play and listen to.

When I first come to a piano, I'll check the pitch to find out how close it is to A440. This is always fun for me, and it tells me a lot about the piano! If the piano is relatively close to pitch, I can tell that either this specific piano holds a tune quite well despite seasonal fluctuations, or the piano owner has been conscious of having it serviced and placed it in a good location, sometimes both.

Usually, if the piano hasn't been tuned for 2+ years, the pitch is lower than it should be, far enough that it requires a pitch raise. I'll take measurements across the piano, because sometimes the bass notes will be relatively close to pitch, but the center and treble sections will both be flat, or vice versa. In rare cases, the piano might even be sharp of pitch! My electronic piano tuning device will make calculations and I make adjustments accordingly.