Is A Piano A String Or A Percussion Instrument?

The piano sits at the center of one of the music’s most enduring debates: Is it a string instrument or a percussion instrument? The answer isn’t black-and-white. Both sides have strong arguments.

Why the Piano Is Considered a String Instrument (Chordophone)

At its core, the piano produces sound through the vibration of strings — typically 200–250 steel strings stretched across a cast-iron frame. When you press a key, it triggers a complex mechanism that causes a felt-covered hammer to strike the string(s), setting them in motion. The vibrations travel across the bridge to the soundboard, which amplifies them into the rich tones we hear.

This makes the piano a chordophone in the most widely accepted scholarly system: the Hornbostel-Sachs classification (developed in 1914 by Erich von Hornbostel and Curt Sachs). In this system — used by ethnomusicologists and museums worldwide — instruments are grouped by how sound is produced:

• Chordophones (3xx) = sound from vibrating strings.
  • The piano falls under subcategory 314.122-4-8: a simple board zither with a resonator box, where strings are struck by hammers and controlled via a keyboard.

Other chordophones include violins (bowed), guitars (plucked), and hammered dulcimers (struck). The piano shares clear ancestry with the hammered dulcimer, an early struck-string instrument that influenced Bartolomeo Cristofori’s invention of the pianoforte around 1700.

Tuning reinforces this: technicians adjust string tension with tuning pins, just like on other string instruments.

Why the Piano Is Often Called a Percussion Instrument

A piano’s sound begins with a strike — the hammer hits the string percussively (a sudden, brief contact). Unlike bowed or plucked strings, there’s no sustained excitation after the initial hit, giving the piano a sharp attack similar to percussion.

In Western orchestral practice, pianos are frequently grouped with the percussion section in scores and ensembles because:

• The player initiates sound via striking (keys → hammers).
• It provides rhythmic drive, accents, and color like drums, xylophones, or timpani.

Many pitched percussion instruments (xylophone, marimba, glockenspiel, timpani) also produce definite pitches, so the argument from the “piano is a string instrument (chordophone)” group’s argument that a “percussion must be unpitched” doesn’t hold.

The Verdict: It’s Both — But Primarily a Chordophone with Percussive Qualities

Most authoritative sources (e.g., Britannica, ethnomusicology references) describe the piano as both a stringed and a percussion instrument. The Hornbostel-Sachs system prioritizes the vibrating medium (strings) over the excitation method (striking), so it’s officially a chordophone. However, the percussive action is undeniable, which is why everyday and orchestral contexts often treat it as percussion-like.

Think of it this way: the piano is a struck chordophone — a hybrid that combines the pitch control and sustain of strings with the attack and articulation of percussion. This duality is part of what makes the piano so versatile and expressive.

At Miller Piano Specialists, we’ve serviced and sold thousands of pianos over the years, and we love this debate — it highlights how fascinating the instrument truly is. Whether you’re tuning strings or admiring the hammer action, the piano remains one of music’s most remarkable creations.

Curious about your piano’s mechanics or need tuning/repairs in the Nashville area? Stop by our Nashville Piano Store or give us a call — we’re happy to geek out over it with you! If you’re looking to purchase, move or service a piano, we’re your one-stop piano store.

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