Clients often wonder why I ask them to turn off ceiling fans, before I tune their piano. It’s not due to temperature or noise – most are very quiet. It is because the sound waves from the piano are bounced off of the fan blades. This causes a “warble” or “chorus” effect, very similar to the “beats” that a Piano Tuner is trying to eliminate. The disturbance is directly related to the speed of the fan – similar to an organ “leslie” effect. To hear this yourself, sit at the piano with the fan on, strike a big chord with the damper pedal (right pedal!) depressed. Now, turn off the fan and listen closely. The warble slows with the decreasing fan blade speed. Many people do not notice this, or think it’s just the way their piano sounds!