When properly cared for, the music from your grand piano is a delight to your ears. It doesn’t take long 
however, before it starts to sound “off”. How often should you have your grand piano tuned? The answer varies depending on the conditions your piano is exposed to, and your personal preferences.
Pianos Exposed to Ordinary Conditions
At minimum, it is recommended that you have your grand piano tuned twice a year. Under ordinary conditions, your piano is not exposed to major climate changes or extreme humidity. Even without climactic fluctuations, your instrument still needs to be tuned semi-annually. Due to the constant pressure & tension on your piano’s structural components, it is continuously going out of tune. Variation in pitch may go unnoticed for awhile, but without regular tuning, your piano will begin to sound unpleasant. Consider having your piano tuned at daylights savings time, or setting up another six month schedule that is easy to remember.
Pianos Exposed to Changing Climates
A grand piano that is exposed to a climate of changing seasons may require a more frequent tuning schedule. The constant variance of humidity in the air as the seasons change takes its toll. To lessen the severity of the weather’s impact, you can place your piano near a wall, away from doors or windows that are opened 
regularly. It is helpful to keep your piano away from fireplaces, vents, or direct sunlight. Even so, you may find that the pitch of your piano to be bothersome with only semi-annual tuning. You may choose to have your piano tuned at quarterly intervals.
Other Times or Reasons to Tune your Piano
Some pianists are very sensitive to “out-of-tuneness”. If this is the case with you, your grand piano can be tuned as often as desired. There is no harm in piano tuning frequently. In fact, concert hall pianos are tuned prior to each performance. If you will be playing your piano for a function, you may consider having your piano tuned beforehand. Additionally, pianos that have been moved to a new location should be tuned.
No matter the climate conditions or personal preferences, it is important to keep your grand piano tuned. The longer a piano is left out of tune, the longer it will take to re-tune. To guarantee the best quality from your instrument, you must set up a regular tuning schedule and stick to it.