What is voicing a piano?
Tone vs Pitch
Every piano has its own unique tone. Tone is different from pitch. Pitch refers to the position of each note in its purest form and is adjusted by the process of tuning. The tone, or sound, of a piano differs by instrument and was likely a big factor in why you chose your piano. Every player has their own preferences, and certain tones pair best with different styles of music. Over time the tone of a piano will change through wearing of the parts, but the original tone can be restored by voicing the piano.
There are many words to describe the tone of a piano: mellow, deep, harsh, brittle, metallic, lively, rich, bright, dark, nasally, glassy, warm, full singing, thin, robust, delicate, soft, sweet, loud, to name more than a few. Some of these descriptions are used by pianists to describe what they hear when they play their instruments. Some describe what pianists want to hear. A good piano has a wide range and with proper voicing should sound even and musical in any register.
How do you know a piano needs voicing?
To determine if they want to request their piano be voiced, a pianist should play a wide range of musical pieces and observe the piano’s current tone. Some voicing changes are difficult to reverse, so they should take consideration and care to explore what sound they want.
A pianist can discuss what they want with their technician. Perhaps they want to restore the piano to its factory original tone, or maybe they have something customized in mind.
Tone to fit the situation
The technician will also take into account how the piano is used. A piano played on a stage sounds different to the pianist than it does to the audience, and this needs to be taken into account. A piano used in a recording studio may need to be voiced to sound more neutral so the changes can be made in the mixing end of the process. Other things the technician will take into consideration are the acoustics of the room and how the piano sounds with the lid open vs closed.
How to voice a piano
Voicing makes many people immediately think of the hammers on the piano, but a thorough technician will ensure other contributing factors are addressed first. To begin with, a piano should be well-tuned. Occasionally a player will request voicing, but then find that the sound they were hoping for was accomplished just by having the piano tuned. This also brings the piano to a good baseline.
If the tone sounds uneven, the technician will check hammer to string alignment, string condition, and other regulation issues that should be addressed before voicing. After going through these steps, the technician will determine what changes to make to the hammer felt. Through time and play, the hammer felt becomes hard, worn, and compact, often creating a tone that sounds too bright and harsh. The technician will vary their approach depending on the type of hammer and the tone they want to achieve.
Some techniques involve poking the felt with needles, with attention to the location, depth, and angle. All seemingly minor decisions yield different results. The hammers may need reshaping, as they become flattened and indented from pounding on the strings. Most hammers can handle being reshaped once in their lifetime.
Technicians also use solutions on the felt to harden the hammer, if needed. The process requires a lot of precision, skill, and experience, and approaching it in an amateur fashion could unfortunately easily destroy a hammer. The technician will carefully voice the hammers to achieve as even a tone as possible across all notes so that the piano has the range and desired sound.
Voicing new pianos
Often new pianos may need some voicing, especially handmade ones that come with slight variations but have loads of potential for the technician to unlock.
How often?
Pianos that receive heavy use may need to be voiced every 1-5 years, so if you are noticing changes in the tone, discuss this with your technician at one of your tunings. Your piano may simply need more frequent tuning or some regulation, or it may need some voicing to bring it back to its former glory.
