Musical instrument repairers maintain instruments so they perform properly. They adjust, repair, replace, install, inspect, clean, and play instruments and parts to maintain them and diagnose problems. Musical instrument repairers work on a number of instruments. The occupation includes piano tuners and repairers, who are often called piano technicians. It includes pipe-organ tuners and repairers and brass, woodwind, percussion, or string instrument repairs.
Piano tuners adjust piano strings to the proper pitch.
A string's pitch relates to its sound. The pitch is the how quickly the string vibrates when it is struck by one of the piano's wooden hammers. Striking the key, the tuner compares the string's pitch with that of a tuning fork. Repairers use a tuning hammer that is also called a tuning lever or wrench. The tuner uses the tuning hammer to turn a steel pin to tighten or loosen the string until its pitch matches that of the tuning fork.