Your piano has approximately 250 strings. These strings are grouped in three-to-a-note (tricords), two-to-a-note (bicords) and single strings (unicords). Due to changes in humidity and from playing, these strings will gain/lose tension over a period of a few months.
Tuning is the process of systematically putting the strings back at the correct tension for each of the 88 notes on your piano. It not only involves making the notes sound correctly when played together but, since most notes on your piano has more than one string, each note has to be correct by itself! During the tuning process you’ll see your tech first insert strips of red felt in between the strings. Doing this will block off the outside two of each set of three strings.
Next you’ll see him/her tune each note of the piano but listening to ONLY one string per key. This is called “tempering the piano.” Once we have one string correct for each of the 88 keys, you’ll see that we then systematically remove the felt and make each note sound correct by itself, which is called “tuning the unisons.”
When properly in tune, all of the strings together exert about 40,000 lbs of tension on the harp of the piano! Many times, if a piano has been neglected for a number of years, it will take three or four tunings over a period of a few months to stabilize that tension again without risking damage to the piano and breaking those expensive strings.
Pianos in a home should be tuned at least once per year, depending upon usage and humidity changes. Most customers who own grand pianos will have them tuned twice per year. Colleges and universities will be on tuning schedules ranging from every two-three months to almost monthly. For concert pianos you’ll see a tech usually tune the piano before the rehearsal and sound check, then tune it again immediately before the performance to ensure the perfection required by the artist!
Action regulation is the adjustment of the mechanical aspects of the pianos to compensate for the effects of wear, the compacting and settling of cloth, felt, and buckskin, as well as dimensional changes in wood and wool parts due to changes in humidity.
The three systems involved in regulation are the action, trapwork (pedals) and damper system. The action is the mechanical part of the piano that transfers the motion of the fingers on the keys to the hammers that strike the strings. It is comprised of over 9,000 parts which require adjustment to critical tolerances to be able to respond to a pianist's every command.
The trapwork is the assemblage of levers, dowels and springs that connects the pedals to the action affecting sustain and dynamics. The damper system is the mechanical part of the piano that stops the vibration of the string when you release the key and is controlled by the key and pedal systems (Piano Technicians Guild).
Many times neither tuning nor action regulation will result in a playable piano! We then get into the area of piano repairs.
Repairs can range from recovering keys to a complete re-string of the instrument. We are very careful to counsel customers about putting more money into a piano than the piano is worth. At that point we will refer a customer to a piano store for replacement!