How the piano came to be: from Cristofori to today – and why it sounds the way it does

Whoever understands how a piano works also understands what matters when buying – and why certain terms (hammer action, resonance, weighted keys) appear in every consultation. So here is the history of the instrument, told in plain language.

The problem nobody could solve for 400 years

Keyboard instruments with strings existed long before the piano. The harpsichord was the concert instrument of the Baroque: every key plucks a string with a small quill – brilliant in sound, but with a built-in flaw: every note is equally loud. Whether you stroke the key or hammer on it, the quill always plucks the same. The clavichord could do quiet and louder, but was altogether so delicate that it barely filled a room – a pure practice and house instrument.

Musicians wanted both: the power of the harpsichord and the expressiveness of the clavichord. Instrument makers bit their teeth out on exactly this for centuries.

Around 1700: an Italian invents “soft and loud”

Bartolomeo Cristofori, instrument maker at the Medici court in Florence, found the solution around 1700: instead of plucking the string, his action lets a small hammer fly against the string – and the trick: the hammer rebounds immediately and lets the string swing freely (the so-called escapement). The faster the key is pressed, the faster the hammer flies, the louder the note. Cristofori called his instrument gravicembalo col piano e forte – “harpsichord with soft and loud”.

1700–1900: from quiet salon instrument to concert thunder

Cristofori’s early instruments still sounded delicate. What followed was 200 years of engineering, driven by composers who wanted ever more – above all Beethoven, who outright wore pianos out:

Why does a piano actually sound so special?

Three components explain almost everything – and all three reappear later when buying a digital piano:

1. The felt hammer. The tone begins with a strike, not with a bow stroke or a breath. This percussive “leap” and the subsequent free decay of the string – starting loud, slowly fading, low notes clearly longer than high ones – is the base signature of the piano sound. And: a firmly struck hammer compresses harder and excites more overtones. Played firmly, a piano sounds not only louder but also brighter. Exactly this you can try yourself in our touch-response listening demo.

2. The soundboard. A vibrating string alone is almost inaudible – it is too thin to move air. Therefore a bridge transfers the vibration to the soundboard: a large plate of spruce, a few millimetres thin, that pushes the whole air in the room as a giant membrane. The soundboard is the piano’s built-in “loudspeaker” – and the reason an acoustic instrument fills the room in a way small boxes struggle to imitate. Half the furniture vibrates along with it: lid, case, even the floor beneath the instrument.

3. String choirs and sympathetic vibration. Almost every note has not one but two to three strings (in the bass one thick, copper-wound one). These “choirs” are never tuned perfectly identically – the minimal beating makes the tone alive. Add the sympathetic resonance: press the right pedal and all dampers lift, and every played note sets dozens of other strings quietly vibrating along – this silvery “carpet of shimmer” is one of the most magical effects of the instrument.

And what does that mean for today – and for the digital piano?

A modern digital piano tries to recreate exactly these three things: the hammer action (hence weighted keys – the fingers should learn the same force control as on the original), the sound growing brighter under a firm strike (good instruments switch between several recording layers depending on strike force, or compute the sound physically) and the resonances (string sympathy, damper noise, pedal carpet). The difference between a €150 keyboard and a €600 digital piano lies almost entirely in these three points – not in the number of sounds.

Put differently: the buying criteria we repeat all over this site are no dealer invention. They are the three answers to the question Cristofori asked over 300 years ago – how do you make a string sing softly and loudly?

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