Piano Tuning & Regulation
What's the difference between tuning and regulating?
Tuning sets the pitch of the strings. Regulation adjusts the thousands of moving parts that make the keys feel right.
Tuning
Tuning is the process of turning the tuning pins to raise or lower the pitch of the strings. A piano has an average of 220 strings, and each must be set to the correct frequency. Beyond pitch, the tuning pin must be set so it doesn't twist or turn and let the string drop. “Setting the pin” is an art that takes years to learn — and it's probably the single thing that separates expert tuners from average ones.
Regulation
Regulation is the process of adjusting all the moving parts of the action to correct specifications. There are an average of 8 adjustments per key — times 88 keys — set to within a few thousandths of an inch to make the roughly 5,000 action parts work correctly. This should be done every few years on a home piano, and is checked before every performance on a concert grand.