A piano tuner is a skilled professional who adjusts the tension of the strings in a piano to ensure it produces the correct pitch. This process involves using specialized tools, such as a tuning fork and electronic tuners, to measure the frequency of each note. Regular tuning is essential for maintaining the instrument's sound quality. Piano tuners often recommend tuning a piano at least twice a year, especially if it is used frequently. They may also provide maintenance services, such as regulating the action and voicing the hammers, to enhance the overall performance of the piano.