Why Spruce Soundboards Still Reign Supreme

Macauley Sykes
Jun 20
9 min read

The piano has seen a dramatic transformation since the earliest days of Bartolomeo Cristofori’s first “gravicembalo col piano e forte” in the early 1700s. From its delicate beginnings in the Italian court to the commanding concert grands of today’s stages, it has continually evolved, with each generation of makers pushing the limits of tone, power, and durability.

At Sykes & Sons Pianos, we spend our days with these instruments — examining, restoring, and cherishing them — and we’re often asked what makes a piano sing. While many elements play a role, the humble soundboard remains one of the most vital, yet misunderstood, parts of any piano’s voice.

In this article, we take you inside the history, the science, and the sheer craftsmanship that keeps spruce wood at the very core of piano soundboards and explain why, even after three centuries, there is still no better choice.

A Brief Journey: How the Piano Grew Stronger and Louder

Cristofori’s earliest pianofortes, crafted at the turn of the 18th century, were groundbreaking yet delicate creatures by modern standards. Their frames were constructed entirely of wood, much like the harpsichords and clavichords they evolved from, and the strings were under relatively low tension. This meant that while these instruments allowed for soft and loud dynamics (the very feature that gave the “pianoforte” its name), their voice was still intimate, ideally suited to the salons and private chambers of European aristocracy rather than the vast concert halls to come.

As music itself evolved, so too did the demands placed on the piano. Composers pushed the boundaries of expression, requiring instruments that could keep pace with their powerful, technically demanding works. Audiences grew larger and concert venues expanded from candlelit parlours to grand public halls, where a piano needed to project its voice above the swell of an orchestra or the murmurs of an expectant crowd.

To answer this challenge, piano makers embarked on a period of remarkable innovation and experimentation throughout the late 18th and 19th centuries. Early pianos featured lighter wire and fewer strings per note, but by the Romantic era, piano makers had increased both the number and the diameter of the strings, allowing for a deeper bass and a richer, more resonant treble. Builders reinforced the piano’s structure, replacing fragile wooden frames with robust cast iron plates capable of withstanding the immense tension of these new, thicker, heavier strings.

The action — the ingenious mechanism that translates a player’s finger movement into hammer strikes on the strings — became more refined, enabling faster repetition and greater control over dynamics and articulation. The primitive knee levers evolved into the modern foot pedals we now take for granted, giving players an unprecedented palette of tonal colour and sustain.

Even the keyboard itself expanded. Where Cristofori’s early instruments offered around five octaves, today’s pianos provide a standard range of seven and a quarter octaves, from a rumbling low A to a sparkling high C. This vast span opened new horizons for composers and performers alike.

Each of these developments made the piano louder, clearer, and more versatile, capable of whispering delicate melodies or roaring with symphonic grandeur. Yet amidst all this mechanical and musical evolution, one vital element remained remarkably unchanged: the soundboard.

Why Does a Piano Need a Soundboard at All?

This thin, carefully shaped sheet of timber, hidden just beneath the taut strings, is the piano’s beating heart. Its function has always been the same: to capture the minute vibrations of the strings and amplify the sound. Think of the soundboard as the piano’s loudspeaker. Strike a string by itself and you’ll hear only a faint ping — the metal wire vibrates, but alone it moves very little air. The soundboard’s job is to catch those vibrations and amplify them into something rich and room-filling.

In a well-designed and constructed piano, the soundboard is perfectly shaped and delicately crowned, so it can flex and optimally resonate. Without it, even the finest strings and the most robust frame can’t deliver the singing tone that pianists and audiences crave.

What Makes Spruce So Special?

So why has spruce, of all the woods in the world, reigned supreme for this purpose for over 300 years?

It comes down to nature’s perfect balance. Spruce is light yet strong, with long, straight fibres that carry vibrations quickly and evenly across its surface. Its specific density and elasticity mean it neither deadens the strings nor overemphasises harsh overtones — instead, it produces a clear, singing tone that blends beautifully through all registers.

Other woods have been tested — cedar, fir, even cypress in certain experiments — but none have consistently delivered the musical warmth and reliable resonance of spruce.

The Legacy of Old-Growth Spruce Forests

Another key factor is where this spruce comes from. The best soundboard spruce historically came from old-growth forests in Northern Europe, North America, and parts of Canada.

These forests, with their cold climates and slow growth cycles, produced tall, straight trees with tight, even growth rings and few knots — perfect conditions for producing resonant timber.

Antonio Stradivari

This discovery wasn’t unique to piano makers. The great violin maker Antonio Stradivari famously selected Alpine spruce for his violins and cellos.

Stradivari’s choice was more than just tradition; it was a master’s understanding of how nature and craftsmanship intertwine.

In the golden age of Cremona’s violin making, selecting the right spruce meant venturing deep into the high-altitude forests of the Alps, often in winter when the trees were dormant and the sap content was lowest. This careful timing ensured that the harvested wood would be lighter, more stable, and less prone to warping as it aged. Beyond that, Stradivari and his contemporaries knew how to season and shape the spruce to unlock its full potential. Planks would be air-dried for years — sometimes decades — allowing internal tensions to settle naturally.

This careful selection and meticulous preparation echo through every note a Stradivarius produces. Even after 300 years, the finest instruments still respond with a nuance and projection that modern builders strive to replicate. It’s a testament to how the simplest material, treated with patience and respect, becomes the heart of an instrument destined to outlive its maker by centuries.

Today, this same storied forest continues to shape the sound of some of the world’s finest pianos. Makers like Fazioli proudly source their soundboard spruce exclusively from the Val di Fiemme, believing it to be the soul of their unmistakable tone. They’re not alone, with other top-tier manufacturers such as Bösendorfer, C. Bechstein, and Steinway & Sons’ Hamburg workshop also turning to this prized Alpine timber, especially for their flagship and custom-built instruments.

The Battle for Spruce and Explorations in Alternatives

By the 19th century, demand for spruce skyrocketed. It wasn’t just pianists and violin makers competing for it. During World War I, spruce wood took on a role far beyond the realm of music. Its unique combination of lightweight and remarkable strength made it an indispensable material for the new and rapidly advancing world of military aviation.

Early fighter planes and reconnaissance biplanes relied on spruce for their structural frameworks, from the wing spars that bore the weight of flight to the ribs and struts that shaped the aircraft’s aerodynamic form. Propellers, too, were often carved from carefully selected spruce, sometimes layered with harder woods to withstand the stresses of spinning at high speeds.

Its flexibility and resilience allowed these fragile-looking planes to endure the constant vibrations and stresses of aerial combat and long patrols. The need for vast quantities of high-quality spruce led to a massive, coordinated effort to harvest and process it quickly. In the United States, this urgency birthed the Spruce Production Division, a special unit where loggers and soldiers worked side by side in remote forests of the Pacific Northwest, felling giant trees under tight military supervision. The same prized trees that once sang as piano soundboards now soared into the skies as the bones of early fighter planes.

By the 1930s and 40s, aviation technology had advanced dramatically, but high-grade spruce was still essential for building and repairing many aircraft. Once again, spruce became a critical material during WW2. While metal airframes were becoming more common in larger bombers and fighters like the Spitfire, a vast number of gliders, trainer planes, and parts of older biplanes still relied on spruce for their main spars, ribs, and other load-bearing structures.

In Britain, large reserves of spruce were controlled and rationed by the Ministry of Supply to ensure that aircraft factories and maintenance depots always had enough. Britain, however, did not have vast native supplies of the best straight-grained spruce, so most of their high-quality timber came from Canada, Norway, or the Baltic states before the war. Wartime shipping constraints, enemy blockades, and the Battle of the Atlantic made these imports incredibly risky.

To address this, the UK government implemented strict controls on domestic forestry, expanding the use of British-grown softwoods like Scots pine and Sitka spruce (planted earlier in the century). Timber yards and sawmills operated under close supervision, and some forests were felled at a scale not seen before, leaving a lasting mark on parts of the UK landscape. Specialist units and civilian timber corps, including the famous Women’s Timber Corps (nicknamed the ‘Lumber Jills’), played a vital role in cutting and processing home-grown timber for aircraft and other wartime needs.

These wartime scrambles for spruce left their mark on the world of instrument making. By the 20th century, much of these primaeval forests had been heavily logged, and piano makers found it increasingly difficult to secure the flawless resonance wood they depended on for their soundboards.

This scarcity pushed some manufacturers to use lower grades of wood or experiment with entirely different materials altogether. Aluminium, steel, and laminates were explored, but none could compete with the resonance of spruce. While metal frames transformed piano design for the better, metal soundboards failed to win hearts or ears. They proved durable, yes — but cold, lifeless, and lacking the subtlety that players and listeners cherish.

A Word About Modern Laminated Soundboards

It’s worth noting that in mass-produced pianos, cost constraints often lead to compromises. Some budget pianos use laminated boards — essentially plywood — instead of solid spruce. While this keeps production costs down, the result is a stiffer, less responsive soundboard with far less warmth and complexity.

When you play such an instrument, you may notice that notes sound flat or lack the rich sustain that makes a piano truly inspiring to play. For casual use, this might be acceptable, but for any serious player, there’s simply no comparison to a proper spruce soundboard, well-fitted and expertly maintained.

A Soundboard for the Next Generation

Thankfully, modern sustainable forestry practices mean that new generations of high-quality spruce can still be responsibly harvested, ensuring that this remarkable wood remains available for future generations of craftsmen, musicians, and music lovers alike. Managed forests, selective harvesting, and careful replanting help protect fragile alpine ecosystems while maintaining a supply of resonance-grade timber that lives up to the standards set by master builders centuries ago.

Leading piano makers and dedicated restoration specialists now work closely with trusted sawmills and foresters, often building relationships that span decades. This ensures that every plank is chosen for its perfect grain, correct seasoning, and the subtle properties that allow it to vibrate freely and evenly. In an age of mass production, this attention to nature’s fine details remains a mark of true craftsmanship.

Restoring a Soundboard: Art, Science and Patience

At Sykes & Sons, we understand that the soundboard is truly the soul of the piano. In our workshop, we handle soundboards with immense care and respect. Some instruments need only minor repairs, while other boards may need careful re-crowning, a delicate process of restoring the board’s natural curve so it vibrates freely again. If age, cracks, or poor storage have taken too great a toll, the complete replacement of the soundboard may be considered.

When a replacement is unavoidable, sourcing the right spruce is critical for restorers. Only timber with straight, uniform grain, minimal knots, and the right growth ring spacing will pass a discerning inspection. Even then, the wood must be seasoned and shaped with painstaking accuracy to either match the piano’s original design or introduce enhancements. This is one area where shortcuts simply do not pay off, and expertise is crucial.

For us at Sykes & Sons, preserving this tradition is about far more than nostalgia or sentiment. It’s about safeguarding the authentic voice and personality of every piano entrusted to our care. A properly restored soundboard does more than make the strings ring louder; it breathes life back into the entire instrument, allowing it to convey the warmth, clarity, and depth of tone its maker originally intended.

A Tradition That Still Sings

Next time you press a key and hear that single note swell and fill the room, pause for a moment to remember what makes it possible. Behind that sound is the quiet work of centuries: forests that grew undisturbed, craftsmen who selected each tree with care and knowledge passed down through generations, and builders and restorers who shape each soundboard until it sings just right.

Every piano, whether a concert grand on a famous stage or a humble upright in a family living room, carries within it this living link between nature and human artistry. Long before microphones, speakers, or digital sampling, it was spruce — light yet strong, resonant yet flexible — that gave the piano its voice. And still today, no modern material has ever truly replaced it.

It’s a humbling thought: that something as delicate as a sheet of wood can take the faint vibration of a metal string and turn it into music powerful enough to stir an audience or comfort a quiet evening at home. It reminds us that some secrets of good sound can’t be rushed or reinvented — they must be respected, tended, and passed on.

So when you hear your piano sing, know that you are hearing more than strings and hammers. You are hearing the whisper of mountain forests, the touch of skilled hands, and a tradition that refuses to fade — proof that spruce, humble and timeless, still holds the soul of the piano.