Action Repair and Regulation
The pressing of a single piano key initiates a sequence of events that concludes when the key returns to its rest position. Between the first event and the last, 30 or more parts move together in a complex dance orchestrated by the piano's designers. It is the sum total of these moving parts for each key that we call the piano's action, and it is the sum total of the adjustment of these parts that we call regulation of the action.
To completely regulate a piano action takes approximately 30 hours. While this isn't a procedure the average piano owner will have to live through (or pay for), it should give every owner some sense of what went into the design and manufacture of that large piece of furniture that takes up so much room in their living room.
In order to pursue a career as a piano technician in the United States today, it is useful for an individual to study the history of piano technology for the last 300 years and to understand how refinements have resulted in the piano action we know today. The depth of that understanding and the ability to apply it to the repair and regulation of piano actions are important attributes that define today's piano technician.