Evolution of Keyboard Instruments — From the Clavichord to the Steinway

Three Lines of Keyboards

The keyboards leading to today’s piano fall into three main lines:

• Organ — sound is produced by air blown through pipes; a church instrument developed from the Middle Ages
• Clavichord — hammered strings, extremely soft, a domestic and practice instrument
• Harpsichord — plucked strings, the principal solo and continuo instrument of the Baroque

The piano is a fusion of clavichord and harpsichord — the hammer principle scaled up to concert volume.

The Clavichord — “My Instrument”

The clavichord developed in the 14th–15th centuries. A metal tangent behind each key rises to strike the string from below when the key is depressed. As long as the finger holds the key, the tangent remains in contact with the string, so vibrato (Bebung) is possible.

• Extremely soft — a solo instrument for a small room
• Beloved for its delicate expression
• Bach, Mozart, Haydn used it at home
• C. P. E. Bach (the son) called it his favorite instrument

“Only the player hears it” — an introspective, intimate instrument. A living tradition of period-clavichord playing continues today.

The Harpsichord — King of the Baroque

The harpsichord (Italian cembalo, French clavecin) appears in the 14th century and becomes the principal solo and continuo instrument from the 16th to the 18th centuries.

Mechanism:

• A jack rises behind each key
• The jack carries a plectrum (once made from a quill)
• When the key is pressed, the jack rises and the plectrum plucks the string
• On release the jack drops back, tilting the plectrum aside, and a damper stops the string

No dynamic variation — no matter how hard the key is pressed, the volume is the same — but the harpsichord’s clarity and multi-manual construction (two keyboards or more) supported a virtuoso art of registration.

Baroque Harpsichord Music

• François Couperin (1668–1733) — the summit of the French clavecin school
• Domenico Scarlatti (1685–1757) — 555 sonatas
• J. S. Bach (1685–1750) — Well-Tempered Clavier, Goldberg, Partitas (detailed in the next article)
• Handel (1685–1759) — suites, chaconnes

The harpsichord was the center of Baroque music, but its inability to shape dynamics finally became a limitation in the mid-to-late 18th century.

Cristofori — 1700, the “Pianoforte” Invented

Bartolomeo Cristofori (1655–1731) worked in Florence as a Medici-appointed instrument-maker. The instrument he invented around 1700 appears in inventory as:

Un cimbalo di cipresso di piano e forte (“a cypress harpsichord that plays softly and loudly”)

That is the etymology of pianoforte (later, piano). His motivation is clear: a harpsichord whose volume responds to key pressure.

Cristofori’s Core Innovation

1. A hammer strikes the string (percussion, not plucking)
2. An escapement mechanism — the hammer, once it has struck, immediately releases and cannot double-strike
3. A damper — the string is free to vibrate while the key is held, and stops on release
4. A backcheck — prevents the hammer from bouncing too high

These are the very elements of the modern piano action. What Cristofori completed in 1700 has not changed fundamentally in 300 years.

The Surviving Cristofori Pianos

Of the roughly 20 he built, three survive:

• 1720 — Metropolitan Museum, New York
• 1722 — National Museum of Musical Instruments, Rome
• 1726 — University Musical Instrument Museum, Leipzig

All are restored to playable condition and can be heard in specialist recitals.

Silbermann — The Meeting with Bach

Gottfried Silbermann (1683–1753) was a Saxon organ- and keyboard-maker near Dresden. From the 1730s he improved Cristofori’s design and supplied more than 15 instruments to Frederick the Great of Prussia.

1747 — Bach’s Visit to Potsdam

In May 1747, the 62-year-old J. S. Bach visited Potsdam to see his son C. P. E. Bach (harpsichordist to Frederick the Great). The king asked Bach to improvise on a Silbermann piano.

On a theme provided by the king, Bach improvised a three-voice fugue. The event grew into The Musical Offering (BWV 1079).

Bach had criticized the earlier prototypes (“weak treble, heavy touch”), but by Potsdam he accepted the improved version. Symbolically, “Bach also approved of the piano.”

Mozart’s Walter, Beethoven’s Érard

From the late 18th into the early 19th century, two schools of piano-making dominate:

Viennese (Stein, Walter, Graf)

• Light touch, clear articulation
• Favored by Mozart, Haydn, and early Beethoven
• Mozart owned an Anton Walter piano (bought c. 1782; on view today at the Mozart Geburtshaus, Salzburg)

English/French (Broadwood, Érard, Pleyel)

• Heavier touch, deeper resonance
• Favored by late Beethoven, Chopin, and Liszt
• In 1817 Broadwood presents a piano to Beethoven. The deaf composer craves volume.

The contrast “light and clear” vs “deep and powerful” continues to this day (Steinway vs Bösendorfer, Fazioli, etc.).

Érard’s Double Escapement (1821)

Sébastien Érard (1752–1831) — French maker. In 1821 he patents the double escapement.

• The same key can be repeated in rapid succession — the hammer resets before it has fully returned
• The decisive invention behind Liszt’s dazzling repeated-note technique
• Liszt himself became a passionate advocate for Érard

This is the basis of the modern piano action — the “double repetition.” Fourteen or fifteen strikes of the same note per second became possible.

The 19th Century — Cast-Iron Frames and Cross-Stringing

The early-19th-century piano still had a wooden frame. It could not withstand the string tension, and volume and structural integrity were limited. Two decisive improvements:

The Cast-Iron Frame (1825)

Alpheus Babcock (US) patents a single-cast iron plate in 1825. The total string tension can now exceed 20 tons.

Thicker strings, higher tension → greater volume, richer overtones. A modern concert grand carries about 20 tons of string tension — the weight of 20 cars.

Cross-Stringing (1859)

Henry Steinway Jr. implements cross-stringing (overstrung) in 1859. The bass strings run diagonally over the middle and treble strings, so that:

• Longer bass strings fit in a shorter case
• The bass speaks from near the center of the soundboard, enriching resonance
• Overall balance improves

The modern piano’s basic design is now fixed. Every maker since Steinway has adopted this approach.

Steinway — Founded in New York (1853)

Heinrich Steinweg (1797–1871) learned piano-making in Seesen, Germany. In 1850 he emigrated with his family to the United States, and on 5 March 1853 he founded Steinway & Sons in Manhattan.

• 1855 — Gold medal at the New York Industrial Exposition for a cross-strung, cast-iron piano
• 1866 — Opens Steinway Hall (2,500 seats) in Manhattan
• 1875 — Opens the Hamburg factory; hence the two lines, NY (Model D) and Hamburg (Model D-274)
• 20th century — Standard in concert halls and conservatories worldwide

Contracted “Steinway artists” agree to play only Steinways. Today, most of the world’s leading pianists are contracted.

20th-Century Rivals — Bösendorfer, Yamaha

Bösendorfer (Austria)

• Founded in Vienna in 1828 (earlier than Steinway)
• Favored by Liszt and Brahms
• Preserves the deep Viennese resonance
• The Imperial model has 97 keys (9 more than 88), used for select works of Bach, Debussy, Busoni
• Acquired by Yamaha in 2008

Yamaha (Japan)

• Founded in Hamamatsu by Yamaha Torakusu around 1900
• From the 1980s, the CFX and predecessor concert grands enter the world standard
• Used at times by Richter, late Gould, and Lang Lang
• The dominant practice piano in the world’s music schools

The arrival of Japanese makers at the top level is an important episode in late-20th-century industrial history. Kawai occupies a comparable position.

Fazioli — A 21st-Century Newcomer

Fazioli was founded in Italy in 1981 — a young maker. Paolo Fazioli set out to build the ultimate concert grand.

• ~100 instruments a year, small and high-end
• Used by Argerich, Sokolov, Fujita Mao
• F308 is 3.08 meters long — one of the largest grands in the world
• Praised for softness and variety of color

A new choice in the 21st century against 20th-century Steinway monopoly.

Electronic and Hybrid — 21st-Century Expansions

• Electric pianos (Fender Rhodes, Wurlitzer) — jazz, rock
• Digital pianos (Yamaha Clavinova, Roland RD, Kawai CA) — home
• Hybrid pianos (Yamaha AvantGrand, Kawai NOVUS) — acoustic action + digital sound
• Silent pianos — play acoustically or record through headphones

In modern Japanese urban housing, demand for silent and digital pianos has become enormous. Very few can keep a real grand at home, but digital keyboards have widened the base of piano education.

Why 88 Keys?

Today’s standard is 88 keys, 7 octaves plus 3 notes:

• From A0 (27.5 Hz) in the bass to C8 (4186 Hz) in the treble
• Covers most of the human audible range (20 Hz – 20 kHz)
• Encompasses the whole compass of the orchestra in one instrument

The 88-key standard settles in the late 19th century. Before that, ranges varied from 61 to 85 keys. Even today the Bösendorfer Imperial (97), Steinway D (88), and various vintage designs differ.

Inside a Modern Concert Grand

A Steinway Model D (274 cm):

Part	Number / detail
Keys	88 (52 white + 36 black)
Hammers	88, hard felt
Strings	~230 (single in the bass, double in the mid-range, triple in the treble)
Soundboard	Single spruce panel
Cast-iron plate	Single casting, ~150 kg
Total weight	~480 kg
Total string tension	~20 tons
Total parts	~12,000

12,000 precisely fitted parts — a modern craftsman’s masterpiece.

Piano Making Compared with the Mathematics Series

The piano is a 300-year craftsman’s lineage — an artefact. In our previous [Lineage of Mathematics] series we saw the 500-year lineage of abstract concepts in mathematics. The two evolve on different time scales, with different dynamics:

• Mathematics — abstract concepts, from one mind to the world (Galois, Ramanujan, Perelman)
• Piano — craft and workshop lineages, family firms and factories (Cristofori, Silbermann, Steinway, Yamaha)

The piano is “a technology essentially complete after 300 years.” Mathematics, by contrast, is still expanding in the 21st century. An interesting contrast.

From This Article to the Next

We have traced 600 years of keyboard history, and especially 300 years of the piano. The next article turns to Bach and keyboard music. The Well-Tempered Clavier (1722, 1742), the Goldberg Variations (1741), the Partitas — Bach developed the harpsichord to its ultimate form, and met Cristofori’s new instrument at the very end. From the peak of pre-piano keyboard music to the dawn of the piano age.