Humidity Control Pianos are made primarily of wood. Wood has many benefits - it is strong, natural, light, beautiful, and inexpensive. However, it is also hygroscopic. This means that if the air around it is moist, the wood becomes moist and swells, and if the air around it is dry, the wood becomes dry and shrinks. In Prince George, the relative humidity of indoor spaces often ranges from below 10% in the winter to over 90% in the summer. These humidity changes have adverse effects on pianos - in the summer, the pitch will go sharp, strings or tuning pins may begin to rust, and keys may feel sluggish or even stick, making playing impossible. In the winter, the pitch will go flat and keys may rattle, making unwanted noise. The repeated swelling and shrinking of action parts will weaken them, requiring minor repairs. Eventually, major components of the piano like the soundboard or the pinblock may become damaged, developing cracks. If a pinblock becomes cracked, the piano will not stay in tune and the piano will probably need to be discarded or sent down to Vancouver for serious repair. Luckily, complete humidity control systems designed specifically for pianos are available which will maintain the piano at an ideal relative humidity of between 40-50%. These systems will minimize the adverse effects of humidity changes and should be installed and serviced by a qualified piano technician.