You've finally done it. After all the time spent saving and searching, after the thousands of dollars spent, you've finally brought home a gorgeous acoustic piano. But your responsibility to your instrument doesn't end after moving it off the showroom floor. It would be unthinkable to pop an uncased violin in the corner, never taking the time to clean or tune it before playing. Forgoing piano maintenance is just as absurd. Whether you've got a $4,000 Cristofori upright or a $216,000 Steinway SPIRIO | r concert grand, you'll need to take a few steps to keep your piano sounding right.
Warner Bros. aside, humidity is the piano's worst enemy. You may have experienced the pleasure of doors sticking during the summer. This happens because wood (the predominant material in your piano) warps in response to humidity changes. Wood will expand when humidity is high and shrink when humidity is low. This expansion can result in minor annoyances and irreversible damage alike. At best, your piano will lose its tune. At worst, your piano will dry out and crack. While keeping humidity stable is more important than achieving a precise number, moorepiano.com notes that 45% relative humidity is a good baseline. Purchasing a single-room humidifier and dehumidifier is an easy solution.
Retire Your Piano Properly
It's tempting to let your piano be the centerpiece of the room. At the end of the day, however, a piano is an instrument, not a piece of furniture. You should close the top (if applicable) and cover your piano when you aren't playing it. This helps keep dust from scratching the finish and, far more importantly, from damaging the strings. Don't place anything atop your piano as objects will absorb the sound. Drinks and plants are particularly offensive (remember, pianos are picky about moisture). If the exterior of your piano gets dusty despite using a cover, you can clean it with a feather duster or a damp cloth.
Hire a Piano Technician
If you have any questions about maintaining your piano, you should see a qualified piano technician. A piano technician is the only person who should touch your piano's interior. At the very least, you will need to hire a technician for piano tuning. The Piano Technicians Guild recommends tuning a piano four times over the first year you have it, then tuning it twice each subsequent year. If your piano technician recommends a different maintenance schedule, heed their advice.
Your piano technician will also need to periodically adjust your piano's mechanical pieces (known as "regulating") and maintain the hammers (known as "voicing"). The bottom line is this: a piano technician is necessary to keep your piano working its best, and you should take their word as law.