"Good" tuning is two different things: accurate (in tune) and stable (stays in tune). Professional piano tuners develop these subtle skills through years of practice.
In the beginning of tuning I tune the first (reference) note: A=440 Hz, aided by the use of the traditional metal tuning fork or an electronic pitch. (The traditional metal forks are highly subject to temperature changes which make them "drift" from the standard pitch. Good piano tuners that use forks usually will take special care to warm up cold forks, or allow them to at least get room temperature before they begin.)
What is A-440? What is standard (ñoncert) pitch? All modern pianos and western musical instruments, from about 1930 to the present day were designed and manufactured with the note "A" (above middle C) to vibrate at the rate of 440 vibrations per second. Standard (concert) pitch A=440 Hz, has been universally accepted as the pitch to which all musical instruments should be tuned. It ensures that when instruments play together they will all be in tune with one another.
Usually after a reference note is established, tuners adjust the pitches of all the other notes relative to each other, based upon the reference pitch.
In other words, after the first note is determined from a reference (a tuning fork or an electronic pitch), a second note is tuned based on its relationship with the first note tuned. The third note tuned may be based upon the second note that was tuned, etc. Therefore, a piano technician needs a reference pitch source, traditionally provided by a tuning tool.
I tune pianos completely by ear without the aid of so-called tuning machines (ETD). Which is better: To tune a piano by ear or electronically?
Whether one can tune a piano better by ear or with an electronic tuning device (ETD) has been a battle for years. Why use your ear when you can tune with a tuning device? Why tune with a device if you can tune by ear?
There's a conception that anyone who uses a machine to tune a piano isn't a real piano tuner. At the same time, someone who just buys a tuning fork and a few tools don't necessarily qualify as a piano tuner. The truth is, aural tuning and electronic tuning are both valid methods of tuning pianos. The electronic tuning is just that an aid to tuning and extremely effective in situations where many tunings are needed quickly, such as music schools, churches, etc.
Piano technicians who use ETD usually do an aural check of the tuning to make certain that the tuning is the best tuning they can render on each piano they service. Therefore, the ear remains the best judge of the quality of the tuning. To the listener, the usual perception is that the piano tuned by ear by an experienced tuner sounds better, more musical than the piano tuned with the help of an electronic aid. How can this be, surely the digital tuner must be accurate?
Tuners call this phenomenon "Inharmonicity". The mathematically-calculated equal-temperament pitch actually sounds out of tune for many keys, getting worse the further you are from the middle, and moreso on smaller pianos with shorter strings. Even if you tune every note perfectly with an electronic tuner, you will not get a very pleasing result. The different lengths and types of strings in a real piano tend to alter their resonant characteristics from the ideal. Every piano must be tuned individually to take account of its size, string length, the condition of the strings, the room and any requests of the pianist.
The biggest problem with ETD devices is dependence upon the device. Some individuals purchase one of the devices and some tools and hang up a shingle advertising tuning services. They don't really grasp exactly what it is they are doing and rely solely upon the ETD, and therefore cannot use their ears for the tuning.
In a piano that has been entirely tuned with an electronic tuner, the top registers will sound flat, and the bottom registers sharp. The 'traditional' tuner usually stretches or sharpens the octaves in the treble to align the harmonic series of each pair of notes. In the bass the lower notes are flattened to achieve the same result. This can only be done by ear.
In practice, only A4 (A above middle C) is tuned to a outside standard pitch, 440 Hz; all the other keys are tuned relative to A4. In fact, a purely aural tuner may just tune the "A" with a tuning fork and tune the rest by ear.
The newest tuning software is superbly accurate assuming that the equipment has been programmed for every single piano it encounters, with all the string lengths and diameters.
Technological progress advances at great pace and in time all these issues will be resolved but that time has not come yet.
Common Piano Repairs:
Pianos are complex mechanisms with thousands of parts and very often these parts break or fall out of adjustment, especially in older pianos. Most pianos require minor repairs during their lives, if they have been tuned regularly, are in need of further attention. For example, noisy and squeaky pedals can be silenced. Keyboard "touch" and response can be adjusted to improve sensitivity, allowing the pianist to play more effortlessly and with greater dynamics and musical expression.
Common piano repairs include sticking keys, buzzing or rattling, broken strings, or broken action parts. They can range from easily and inexpensively repaired to quite costly. It's important to keep the instruments in good health and prevent expensive damage that can result from an inexperienced technician.
How often do pianos require tuning?
New piano strings require some time to achieve the proper tension to hold their tunings since they are stretching under considerable pressure. For this reason, it is necessary tuning pianos 3 - 4 times during the first year and twice a year thereafter for pianos used casually. For pianos that are used a number of hours a day, such as those used for piano lessons and in school practice rooms, tuning may be required every 1 - 3 months to keep it in proper tune. Seasonal changes and climate also affect the frequency of piano tuning needs.
Even if a piano is not played, the string tension will gradually lessen over time, thus the piano will go out of tune. It's important to keep a piano in tune, not only for the ear of the player and listeners, but for the health of the instrument. If allowed to go too long, it requires increased adjustments to bring it back to the concert pitch and the stability of the tuning is decreased, meaning it will not last as long.
Should a Piano Tuner be able to play the piano?
It is my opinion that a tuner should be able to play the piano for the following reasons:
1. There needs to be an appreciation of the variance in the tone of each note which can be detected by playing the piano once the tuning has been completed.
2. The touch factor which embraces repetition, depth of touch, weight of touch, can hardly be assessed if the piano is not played by someone who is a competent musician.
3. The efficiency of the pedal mechanism can best be assessed whilst playing the piano
4. And finally in order to be able to communicate with and understand the customer who is a musician.