Before we even get started, I can hear some of you out there shouting “WOOD” …and – while that’s a partially correct – it’s an absolutely incomplete answer. Also, with no qualifiers, the word “WOOD” is woefully imprecise since not all woods are created equal. Balsa wood, for example is very light, but not very strong. Oak wood is very heavy and very strong. Neither make ideal “WOOD” for an entire piano. Why? Well, to adequately explain this topic, we’re going to have to dig a bit deeper.
WOOD
Bosendorfer pianos are on of a very few premium piano companies that still build their grand piano rims out of solid spruce. Most companies (like Steinway and Mason) use laminated rims.
Wood makes up over 80% of most pianos made today. At a glance, you can tell the quality of a piano by the types and quality of woods they use. Better piano manufacturers will select specific woods like spruce for their soundboards and keys. …but spruce is very expensive so most manufactures (with the exception of Bosendorfer) use as little of it as they can. For structural elements that are less involved in producing the piano’s tone, most builders want a hard, durable wood that is more affordable. Let’s look at the two basic types of wood – hardwood and softwood.
Hardwoods are used for furniture and structural elements. Piano legs, framing, braces, action parts and supports might be built out of walnut, maple, mahogany, birch, ebony, or beech woods. Piano builders use hardwoods anywhere a soft wood (like piano keys, key action parts and hammers) might experience too much wear and tear with use. Piano keys are an excellent example of this. The keys themselves are often made of spruce and then capped with pieces of maple to prevent lateral wear and tear along their balance points. Piano bridges are often made of or capped by hardwoods to prevent the piano’s strings from digging into them over time. Almost all piano pin blocks are made from maple to provide the best grip on the tuning pins for many years to come. Hardwoods provide durability and strength that help to prolong the piano’s life.
These keys are made of spruce (a soft wood). To prevent lateral wear and tear from playing, Baldwin has installed hardwood key buttons where the metal guide posts pass through the keys.
Soft woods, by contrast, are much better at transmitting sound than hardwoods. Woods like spruce, cedar, ash, and alder are often used for musical instruments based on their unique tonal characteristics. …but it’s not enough to merely select a species of wood. The quality (or grade) of that wood is also vital to its function. There are vast differences in the quality of spruce, for example. Spruce from very cold climates grows slowly and has a very close grain pattern (The grain is the dark lines running through the wood.) that more efficiently transmits vibrations from the strings to the piano’s rim and back. Some soundboards in high-end pianos use wood that was so slowly grown, the wood may have 20 or more grain lines per inch! Of course, this high-quality, slow-grown wood is incredibly expensive so only the most expensive pianos use it. Most good quality pianos out there are about 8-15 grains per inch. Lower-end pianos may use most affordable trees that were grown more quickly and, thus, have less than 8 grains per inch. Tone wood (a generic term for woods used in soundboards or musical instrument cabinets) must be free of knots or blemishes to produce the very best sound.
Some pianos use less wood than you might think! In fact, to further cut costs, many modern piano builders use laminated wood or solid-core plywood with veneers for their cabinets and lids. This helps them provide a durable piano with a decent performance at a much more affordable price point. Only the most expensive premium pianos still build their instruments out of solid wood.
METAL
The cast-iron plate of this Yamaha grand piano holds the 22.5 tons of tension from the steel strings and tuning pins.
Second only to wood, metal is one of the most important materials found in pianos. Pianos have either a sand or vacuum-cast iron plate that supports the strings and stabilizes the cabinet (Without a cast iron frame to help hold the 22.5 tons of string tension, modern pianos would implode. I have actually seen low-quality pianos twist themselves into a warped shape because they were not properly built to withstand the string tension.). They also use steel for things like tuning pins – which are usually nickel-plated to prevent corrosion – and piano strings! Most piano builders also wind copper around the bass strings to produce more powerful bass tones. (Fun Fact: if bass strings did not have copper wrapping, a medium-sized 6-foot grand would need to be 30 feet long to have near the same sound!) Most piano builders use some form of aluminum for action rails (the metal framework that holds the key action and hammers in place above – or in front of – the strings). Finally, high-quality piano builders use nickel or brass for pedals, hinges and hardware. As with wood, the quality of the metal used (and the method in which it was shaped, finished, etc.) determines the quality of its performance and, thus, the quality of the piano in question.
LEATHER AND FELT
Here you can see white, purple, green and red felts – all doing different things as well as light brown buckskin to the left of the hammers and underneath the hammer shanks.
Interestingly enough, early pianos of the 1700’s used leather to cover their hammer heads. In fact, deer leather was commonly found covering piano hammer heads up until the 1850’s (Deer leather is very durable but it also has varying degrees of hardness and softness which can drastically affect the hammer’s tonal properties.). After 1926, felt and leather were used in different configurations by different manufacturers, but eventually most manufactures switched to customized felt blends for piano hammers.
Since the 1700s, buckskin leather has been a traditional material used in piano actions. Much like the cartilage that pads our vertebrae and prevents the bones from rubbing against each other, buckskin leather acts as a bumper, padding and even a “lubricated barrier” between piano action parts. However, as pianos have become more refined it’s become more important that the softness, suppleness, weight, and thickness be super consistent. This costs a lot of money and manufacturers are always looking to preserve quality while reducing cost. This has led some companies to experiement with synthetic leathers. Some now use a synthetic leather called Ecsaine, which has all the good qualities of buckskin leather, but less inconsistency from piece to piece.
You’ll also find felt woven through the top of the piano strings (usually it’s red, brown or blue) and used on the dampers (usually white) to stop the strings from ringing. Piano builders also use felt in many places for bushings, for padding, or to reduce noise (like on the pedals). Some pianos have a “practice pedal” which, when engaged, lowers a strip of felt between the hammers and the strings. The hammers strike then strike the strings through the felt, somewhat muting the piano’s volume.
PLASTICS
Plastic (“ABS,” “resin,” or “carbon fiber”) action parts are cheaper to make and easier to change, but pianists overwhelmingly prefer an all-wood grand piano action.
With new technologies come new materials and the piano industry – though known for its hesitancy to try new things – is not immune. Almost every major piano manufacturer has – at one time or another – experimented with using plastic in their piano actions. The idea was that plastic would hold up better to changes in temperature and humidity, it would be easier and less expensive to make, and it would offer more consistency than wood – especially in the action where most of the components are very small and more fragile. Most major brands (like Yamaha and Steinway) quickly abandoned this material and resumed using wood once they saw the reaction pianists had to the material. Few major performers liked the feel of a plastic action. Also, as the plastic components aged, they became brittle and began to crack, break or break down – causing even more problems for the owners. Today, only a few piano companies still promote plastics (usually called “Teflon,” or “ABS,” or “carbon fiber”) in their piano actions because they don’t deliver enough benefits to outweigh the backlash from players who prefer the natural “bend and give” of a real wood action. Today, plastics are most often found in areas where they don’t impact a piano’s performance: a lid prop, a front panel latch, key tops, etc.
OTHER MATERIAL
Of course, there different types of glue used in specific areas. Many pianos have a shiny polyester resin finish which is basically a non-porous, very hard plastic. Some manufacturers use medium-density fiberboard (MDF) in non-structural areas. If you have concerns about how the piano you’re considering is made, contact us or ask your local Registered Piano Technician. These construction components can greatly impact your piano’s performance and value over time. It’s important to know what you’re getting into.
CONCLUSION
All pianos are made of similar “stuff,” but – just like all cars have an engine, body, seats, and tires – the QUALITY of all that “stuff” is what determines whether you have a “Yugo” or a “Rolls Royce.”
