Piano Tuning Day (Piano Choritsu no Hi)

What Is Piano Tuning Day?

Every April 4th is "Piano Tuning Day" (Piano Choritsu no Hi). It was established in 1993 by the International Association of Piano Builders and Technicians (IAPBT), and in Japan the Japan Piano Technicians Association has held commemorative events since 1994. The date was chosen because the "A" of "April" matches "A," the reference pitch used for tuning, and that pitch has a frequency of 440 Hz, which gives April 4th. It's a day to turn our attention to the tuners who support the sound of the piano and to deepen our appreciation of music.

The Structure of the Piano and Its Enormous Tension

Despite its delicate tone, the piano is an instrument that holds great force inside.

• Tension said to reach about 20 tons: A grand piano has more than 200 strings, each under strong tension. The combined tension of all the strings is said to reach about 20 tons, and a sturdy cast-iron frame is used to withstand it.
• An instrument that slowly changes: Pianos use many natural materials such as wood and felt. Because these materials expand and contract with changes in temperature and humidity, the piano gradually goes out of tune even if no one plays it. That's why regular tuning is essential.

The Reference Pitch A = 440 Hz and the Tuner's Skill

Creating a beautiful sound requires both precision and an ear backed by experience.

• The 440 Hz standard: At an international conference held in London in 1939, it was agreed that the reference pitch "A" would be 440 Hz. In practice, orchestras and concert halls often tune a little higher, such as 442 Hz.
• Equal temperament and "beats": Pianos are generally tuned in "equal temperament." Tuners listen for the "beats" that occur when two notes are played together, adjusting the tension of each string one by one.

Interesting Facts About Piano Tuning

• Tuning, regulation, and voicing: A tuner's job isn't just adjusting pitch ("tuning"). "Regulation," which adjusts the movement of the keys and hammers, and "voicing," which adjusts the hardness of the hammer felt to even out the tone, are also important parts of the work.
• Hammers made of wool felt: The hammers that strike the strings are covered in felt made from compressed wool. After years of playing the felt hardens and the tone becomes harsher, which is corrected through voicing.
• The piano's full name: The piano was invented around 1700 by Bartolomeo Cristofori in Italy. At the time it was called the "gravicembalo col piano e forte" (harpsichord with soft and loud), and "pianoforte" and "piano" are shortened forms of that name.
• Beethoven and the piano: There is an anecdote that Beethoven, after losing his hearing, held a wooden rod in his teeth against the piano to sense the sound through vibration.
• Thousands of parts: A piano is said to be made up of thousands of parts, including the "action" that transfers the movement of the keys to the hammers.

Tips for Marking Piano Tuning Day

• If you have a piano at home, check when it was last tuned and schedule the next tuning
• Listen to a piano concert or recording and think about how its sound is supported by the work of tuners
• Watch a video showing a piano being tuned to see the intricate action mechanism behind the keys
• Following the idea of tuning as "setting the standard," review your daily rhythm and work routines for the new fiscal year

A Single Well-Tuned Note Creates Beautiful Harmony

April 4th is a day to look at the tuners' work behind the sound of the piano. Just as a piano that has drifted out of tune can be brought back, our daily lives can regain a comfortable rhythm when we stop now and then to reset. Today, why not listen to a favorite piano piece and savor its sound?