When To Tune

The key here is regularity.

Ideally I'd like to see every piano tuned with every change of season.  That's four times a year.  This level of frequency gives your instrument the best chance of responding appropriately to subtle changes of humidity and temperature. A tuning with every season ensures that the strings of your piano maintain optimum tension and therefore optimum strength. Certainly if your piano is being played for more than an hour a day three times a week this is really the best care you can take of your instrument.  An added bonus is that less mundane maintenance needs to be done such as vacuuming (not my favourite part of the job!) 

I recognize that four times a year may be a stretch financially especially for someone whose piano is not being played all that often.  In that case I recommend twice a year.  This gives the piano an opportunity to adjust to the two major climate changes of the year winter/spring and fall/winter.

Failing that the bare minimum really should be once a year even for a piano that is not being played.

Think of it this way.  Regular tuning builds the strength and memory of your piano's strings.  Whatever the schedule you choose consistency ensures that your strings will fluctuate less and therefore create less havoc on other parts of the piano.

Besides the added bonuses for me there are some for you.  Regular tunings save you money.  They allow me to prevent damage that would otherwise cost you many dollars in repairs.  They allow me to inspect the many felt parts of the piano for both wear and insect damage.  They reduce the need for costly extras such as pitch raising, an extra step needed to bring a piano that is very flat up to tune. Pitch raising works in the short term but creates a deficit in the piano that will affect it's stability in the long term.  This can be corrected but it will be an uphill battle.

I am happy to work with clients to arrange a schedule that best meets both their needs and the needs of their piano.