Piano maintenance

The piano requires various forms of maintenance to produce its best sound. Maintenance is also important for the appearance of the piano.

Pianos that are prized by their owners are tuned regularly, usually once every six months for domestic pianos, and always just before a performance in concert halls. The longer a piano remains out of tune, the more time and effort it will take for a technician to restore it to proper pitch. When a piano is only slightly out of tune, it loses the glowing tonal quality characteristic of a freshly tuned piano, especially because each note in the middle and upper range is sounded by more than one string, and these may get slightly out of tune with each other. Pianos that are more than slightly out of tune tend to be unpleasant to play and listen to, to an extent that varies with the ear of the listener. A tuning hammer and tuning mutes are the main tools that piano technicians use. Some tuners use pure aural techniques while some tuners use electronic tuning devices. Formally trained and experienced tuners find that the use of electronic tuning devices is unnecessary, important elements associated with trained aural tuners are often left out by those relying on electronic tuning devices. Consistent errors have been known as a result. These devices often attract the untrained operator in an endeavour to circumvent the need for formal training.

Pianos go out of tune primarily because of changes in humidity. Tuning can be made more secure by installing special equipment to regulate humidity, inside or underneath the piano. There is no evidence that being out-of-tune permanently harms the piano itself. However, a long-term low-humidity/high humidity environment will eventually cause the soundboard to crack and the keys and other wooden parts to warp.

There are a growing number of musicians and composers who are tuning the piano to non-standard tunings, in order to achieve different kinds of harmony not possible with the standard 12-tone equal temperament tuning (normally found on the piano). Examples of such persons are La Monte Young, Terry Riley, and Michael Harrison – to name a few. Their tunings create never before heard of combinations of intervals (some large and some "micro") that lend themselves to many beautiful and interesting new harmonies, scales, and textural effects not possible in equal temperament. Of course, these brands of tuning are limited by the internal structure of the instrument itself. One must be very careful because the piano can only hold so much tension before it breaks.

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Wikipedia