ACHIEVING A QUALITY AND STABLE TUNING.
I tune pianos by ear without the aid of an electronic tuner. This method is preferred by musicians and professionals.
Electronic tuning devices have their place in checking a piano’s pitch prior to tuning and for use in rough pitch-raising applications. I rely on my ear for all fine work often needing to check over my tuning twice to achieve this.
OTHER FACTORS AFFECTING TUNING STABILITY
Piano age and quality
New pianos hold their tuning better than older pianos. They have stronger frames and are structurally healthy enough to withhold the 20 tonnes of tension at the concert pitch. Pianos over 50 years old vary a lot in their condition. In many cases, the strings, pin block, soundboard and bridges are too old to maintain the tension for concert pitch, so the tuning stability may be compromised.
Climatic factors
Humidity fluctuations are the biggest issue in regard to tuning stability. As the humidity changes with the seasons, string tensions change and the soundboard swells and contracts. All pianos, unfortunately, drift flat in time. Interestingly though, a piano can also drift sharp in seasons of high humidity as the soundboard swells.
Placement
Avoid an outside wall that gets direct sunlight. Avoid placing the piano near artificial heating, especially heat pumps and ducted heating. Avoid putting pianos in excessively damp or drafty conditions.
In hot and humid climates, a low-wattage dehumidifier bar and humidistat are recommended as they control the environment inside the piano case, stabilising the humidity between 30-55% which is optimum for pianos.
Usage
If a piano is played a lot, it will require more maintenance. With extended use, the action will need periodic adjustments to keep the touch feeling nice and responsive.
In time, the hammer felts also formed grooves and flattened in shape as they hit the strings. The tone then changes and becomes harsh. Voicing is a process where the hammer felts are carefully pricked with fine needles and shaped to keep the tone at its sweetest.
If you don't play your piano enough, though, other problems of stiffness and sticking keys will present themselves!
Piano moving
Moving pianos is a job for an expert. A piano weighs upwards of 250 kg and has an awkward centre of gravity. Save your back; I can put you in touch with a piano moving specialist who will move your piano without damaging it or your floors in the process.
Moving a piano from one location to another also affects its tuning. Pianos don’t generally “bump” out of tune in the moving process; rather, it's just the conditions of its new home that a piano will happen to adjust slightly.
I advise also waiting a couple of weeks after a piano moving operation before tuning.