What is Key Weight?
It is the combination of the amount of force it takes to depress a key and the maximum weight a key can hold prior to returning under its own weight.
What is Balancing?
This is equalizing the Key Weight across the entire piano for maximum control and player health.
When should this be done?
After a piano has been fully regulated and its friction equalized. Friction Equalization consists of checking all pins and friction points to make sure they are all the same.
Why should I have Key Weighing and Balancing done?
Control – When all the keys take the same effort and return the same this allows for best dynamic control and equal speed.
Health – If you experience sore wrists, forearms, shoulders, or back, your keys might be too heavy or too much friction is impeding their movement.
Music – If what the performer is playing is a lighter quicker period, or a more dynamic and romantic period, the amount of force or effort needed can have a great effect on tone.
Hammers and their role – Another route and possibility is the hammers. Their weight directly affects the weight on the key, by switching to lighter or heavier hammers not only do you effect the key, but also the inertia of the hammer and it’s overall force and power.