Piano Tuning, Servicing & Repairs
Many factors cause pianos to go out of tune, particularly atmospheric changes. For
instance, changes in humidity will affect the pitch of a piano; high humidity causes
the sound board to swell, stretching the strings and causing the pitch to go sharp,
while low humidity has the opposite effect.
Changes in temperature can also affect the overall pitch of a piano.
In newer pianos the strings gradually stretch and wooden parts compress, causing
the piano to go flat, while in older pianos the tuning pins (that hold the strings in
tune) can become loose and don't hold the piano in tune as well.
Frequent and hard playing can also cause a piano to go out of tune.
For these reasons, many piano manufacturers recommend that new pianos be
tuned four times during the first year and twice a year thereafter.