1. Why the Piano Counts as Both a String and a Percussion Instrument
The word "piano" comes from an instrument catalog description meaning "loud and soft." The harpsichord, used before the piano, was difficult to play with dynamic changes. What family does this instrument, which can play both loudly and softly, belong to? The piano is a keyboard instrument that produces sound by striking strings with hammers. Because it has features of both percussion and string instruments, it is classified as a "hammered string instrument." Inside, more than 200 special steel strings called music wire are stretched [1].
If we classify keyboard instruments by how they make sound, the piano is in the same group as the clavichord and harpsichord: "chordophones" (instruments that vibrate strings). The organ and accordion are "aerophones" (vibrating air), the celesta is an "idiophone" (the body vibrates), and synthesizers or digital pianos are "electrophones" [2]. So, the answer is that the piano is related to string instruments, but striking them makes it close to percussion. How does the mechanism work?
2. How Keys, Hammers, Strings, Dampers, and Pedals Make Sound
When you press a key, a connected hammer strikes the string. The damper is a part that stops the string from vibrating and silences the sound, except when the key is pressed. Grand pianos have 3 pedals: the damper pedal, the soft pedal, and the sostenuto pedal [1].
The harpsichord, used before the piano, works differently. When a key is pressed, a part called a jack rises, and its plectrum (a claw-like pick) plucks the string from below to above. The volume depends very little on how hard you hit the key [4]. In contrast, the piano can change volume and tone color based on how hard you press the key [6]. The name "piano" comes from this ability. So, when and who created the piano?
3. How the Piano Began in Italy Around 1700 and Reached Its Modern Form in the 19th Century
Tracing piano history leads to a record in a 1700 instrument catalog. From then until the 19th century, the piano changed shape significantly. It is believed that Bartolomeo Cristofori of Italy invented the piano. The first reliable record is a 1700 catalog from the Medici family in Florence, listing an instrument that "plays loud and soft." The word "piano" was born from the way this catalog was written [3]. The oldest surviving piano was made in 1720 [3].
From around 1790 to 1860, the piano changed greatly from the instruments of Mozart’s time to the form close to today’s pianos [1]. In 1821, the "double escapement" was developed to make fast repeated notes easier, and a patent for the iron frame was taken out around 1825 [1]. In Japan, it is said that Siebold brought a piano in 1823, and that piano remains at the Kumagai Art Museum in Hagi City, Yamaguchi Prefecture. The first domestically produced piano was made in 1900 by Nippon Gakki Seizo (later Yamaha) [1]. The piano’s shape has changed over time. The number of keys has also changed from the past to the present. Why is it the current number?
4. How the Piano Gradually Came to Have 88 Keys
The number 88 was not decided from the start. The number of keys gradually increased over time. Today’s ordinary piano has 88 keys: 52 white and 36 black. The range spans 7 octaves and a minor third, from the lowest note A to the highest note C [1].
In the past, there were fewer keys. Cristofori’s 1720 piano had 54 keys [3]. Pianos in Mozart’s time had about 5 octaves, and during the 19th century, the range expanded to 7 octaves or more, which is the current range [6]. Many old pianos had 85 keys, and some manufacturers made pianos with 92 or 97 keys [1]. The 88-key standard began to be made around the late 19th century and became standard after World War I. There is an explanation that "it is the limit of what humans can hear as distinct notes," but this is stated as "it is said," and the exact reason is not known [1].
5. How Composers Wrote Music to Fit the Changing Piano
The piano can change volume by key pressure, its range expanded in the 19th century, and pedals allow sounds to connect or overlap [6]. This was a major attraction for composers. Mozart wrote concertos and sonatas for the fortepiano in Vienna. Beethoven used the range of Broadwood pianos, which exceeded 5 octaves. Chopin is often associated with Pleyel pianos, and Liszt is introduced as one who used Erard pianos with double escapement for fast repeated notes [6]. However, composers did not use only one manufacturer; it was not a one-to-one match.
As pianos became cheaper, they spread into homes. It became possible for one family member to play newly published songs from simple sheet music for everyone to listen to [6]. It is thought that many songs were written because these reasons overlapped. As the piano spread, the harpsichord lost its mainstream position. How do the piano and these similar instruments differ?
6. How Grand Pianos, Upright Pianos, Digital Pianos, Harpsichords, and Organs Differ
A grand piano places the frame and strings horizontally. It is divided into concert grand, parlor grand, and baby grand by size. An upright piano places the frame and strings vertically, so it takes up less space. A digital piano does not use physical sound sources but creates sound with electronic circuits [1].
The harpsichord plucks strings and is difficult to play with dynamics. It lost its mainstream position when the piano spread in the late 18th century [4]. The organ sends air through pipes to make sound, and the sound continues as long as the key is pressed. In a piano, the sound fades when the key is released. Organs also have keyboards played with feet [5]. Keyboards (like synthesizers) are electronic instruments that make sound with electricity [2]. The melodica used in schools is an aerophone that sounds by vibrating air [2]. So far, we have looked at the instruments. On the player’s side, why can pianists move their fingers so fast?
7. What a 2013 Study Found About Pianists' Finger Speed and Movement
In a 2013 study, 12 advanced pianists played a 5-note melody at a very fast tempo. Their finger, hand, and arm movements were recorded with 3D motion capture. The speed was 7 to 16 notes per second [7]. The knuckle joints were most involved in the up-and-down movement of the fingertips. It is reported that pianists with more efficient movements also had higher accuracy in timing and force [7].
In a 2012 study, 5 pianists played excerpts from 30 songs at normal and fastest speeds. Even at faster speeds, the combination of finger movements remained the same as at normal speed. It was found that the ability to move fingers independently does not change with tempo. This property may be specific to skilled pianists [8]. In 2025, 118 pianists wore a device like a robotic glove (an exoskeleton). The device moved their fingers in motions close to fast piano practice. As a result, they could play faster with one hand, and changes were reported in the part of the brain controlling movement [9]. This is still an experimental study and not immediately usable for general practice. Thus, finger speed may involve movement efficiency and the ability to move fingers separately. However, why this happens is still being researched.
8. How You Can Check These Facts Yourself
The contents of this notebook can be checked with public materials and familiar instruments. Today, you can listen to the difference between pressing the same key softly and pressing it hard. With a piano or a digital piano where sound changes with pressure, you can hear the meaning of the name "piano" ("loud and soft") [3]. In a music room or instrument shop, compare a grand piano and an upright piano. You can see the difference in the direction of the strings and hammers. If you write down just one word that interested you, it becomes an entry point for further research. "Damper" or "hammered string instrument" is enough.