Piano tuning is a service where each tone of an instrument is given a proper frequency. What is more, the task of a piano tuner is to adjust a pitch of tones to achieve a harmonic sound on the whole keyboard.
Technically speaking, piano tuning is just turning and tilting tuning pins to achieve the correct tension of the strings. A tool used for twisting tuning pins is called a tuning lever. Using it requires experience and skills. Every movement, even the most subtle one, results in the considerable change of pitch. This is why the first step is to listen to the sound, and then correct it. Never the other way round. Using tuning lever unskillfully – to fast, or violently can harm the ability of the piano to stay tuned.
Keeping in mind that the standard number of keys in a piano keyboard is 88, and more than a half of keys have more than one string, a piano tuner has to be well prepared to give every string a well harmonized tone. Each string is tuned separately. In order to mute adjacent strings and listen to the sound of only one string, a piano tuner uses a felt strip or wedges.
photo sources: http://pim3.detwiler.us, http://tuningyourpiano.com
If we tuned a piano giving each note a frequency that is shown by an electronic tuner, each note would have a nice sound, but not all intervals would be harmonic.
It results form Pythagorean comma which says that while dividiing an octave to twelve equal semitones, to achieve full octave 1/9 of tone will be missing. Because of that the temperament is required.
Temperament is setting the proper consonance between particular intervals. There are different methods using different intervals. Some methods use for example: the fifth and octave, the fifth and fourth, the third and sixth, the third, fourth and fifth. In the case of tuning by the fifth and fourth, the fifth has to be narrowed while the fourth has to be expanded.
Temperament is setting in temperament area – twelve notes. These are usually those between a0,a1 octave. Set measures between tones are repeated trough all keyboard.
A piano tuner sets also the base tone before setting the temperament. Usualy it is the primary sound – a1.
Since1939 the standard frequency for the a1 note has been 440 Hz. Formerly, the standard frequency for a1 was 435 Hz. It was the Paris standard. Generally speaking, piano tuners tuned to a lower a1 frequency of even 415 Hz. If the instrument is old it is better to leave the present pitch. Trying to make it higher may result in a danger of breaking the strings, or losing tune quickly. Nowadays piano tuners set 442 Hz for a1 tone. The sound of a piano tuned this way is more clear. Musicians who play wind and string instruments find it easier to perform on a little higher tune. To make the cooperation between pianists and these musicians easier, pianos are tuned also a bit higher.
The source of a1 for piano tuners is a tuning fork. They use it in a classical or electronic form.
tuning fork – It produces a sound after being hit. Usually it has 440 Hz pitch.
photo source: http://slowodnia.files.wordpress.com
- electronic tuner – It has different options such as a recognizing tone,a frequency graph, playing of a sound of any frequency. It very often has a built-in metronome.
- photo source: www.phy.duke.edu