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Petroleum in Real Life: Piano keys

You’ve heard the expression, “tickling the ivories”: but did you know pianos since the 1970s use plastic key tops? And for good reason.

‘Tickling the ivories’ is a euphemism for playing the piano that’s persisted to today, even though piano manufacturers no longer use ivory in their manufacture—and for good reason.

Most pianos have 52 white keys and 36 black keys for a total of 88 keys. In acoustic pianos, the keys themselves are made of wood—often spruce or basswood. It is only the thin top of the white keys that is made of ivory or plastic. (The black keys are made of ebony or another hardwood that’s been stained black.) The plastic often used for piano key tops is a kind of acrylic called ABS - acrylonitrile butadiene styrene – an opaque thermoplastic polymer. Thermoplastics like ABS liquefy, which allows them to be injection molded and shaped.

Low- to mid-end digital pianos will use keys that are 100 per cent plastic, while high-end digital pianos have keys similar to their acoustic cousins.

Ivory Be Gone

The earliest pianos built 300 years ago had keys that were made entirely of wood. But then ivory became a preferred material due to its polished appearance, durability and texture.

Ivory from elephant tusks is no longer used to make piano keys and there is a global ban on trade of ivory. Unfortunately, illegal poaching of elephants continues today.

Ivory typically comes from the tusks of elephants. Global trade in ivory in past centuries led to the slaughter of millions of these majestic creatures. International trade ivory from Asian elephants was banned in 1975 when the Asian elephant was placed on the endangered species list. In 1990, a global treaty was signed, banning trade in all kinds of elephant ivory. Unfortunately, illegal poaching of elephants for their ivory continues today. However virtually all pianos made since the 1970s use plastic for their keytops or keys.

Playing: Ivory vs. Plastic 

While pianos with ivory are no longer constructed, there are still many older pianos with ivory keytops in use.

Some piano players prefer the classic feel of ivory due to its porosity, which provides better responsiveness. Similar to tire tread, a porous texture provides traction for the fingertips. The flipside of this argument is that ivory’s natural porosity makes these keys harder to clean.

‘Piano man’ Billy Joel performs in New York in 2008. Credit: Anthony Correia / Shutterstock.com

Beyond the critical factor of conservation, plastic keys are also less expensive, easier to work with, and less prone to damage than ivory, which chips and cracks easily with abuse or temperature variations. Ivory keys also yellow over time.

A complaint about early generations of plastic piano keys was that the keys felt slippery. However, improvements in plastics technology have allowed for the creation of plastic materials with grippier textures, some that are very similar to ivory. Yamaha, for example, uses mineral plastics to create a simulated ivory material it calls Ivorite.

"I am a piano player. And I realize that ivory piano keys are preferred by some pianists…. But a preference for ivory keys does not justify the slaughter of 96 elephants every day. There are other materials that can be substituted for piano keys. But magnificent creatures like these can never be replaced."

Billy Joel

A Brief History of the Piano

The piano, or the gravicembalo col piano e forte, as it was originally called, first came to be in the shop of a harpsichord maker named Bartolomeo di Francesco Cristofori in the town of Padua, Italy. The year was 1709. By the eighteenth century, the piano had dramatically risen in popularity, surpassing its predecessor, the harpsichord. The great advantage of pianos is their ability to play notes softly (pianissimo) or strongly (forte) based on how hard the keys are pressed.

Pianos had their heyday in the 1910s and ‘20s, when they became a mainstay in the middle-class North American household. By the 1930s, with the coming of the Great Depression, as well as the advent of the radio and phonograph, the piano’s popularity started to wane.

Today’s Piano Market

Research firm IBISWorld notes that sales of acoustic pianos have declined over the past ten years as consumers purchase more digital and electric pianos. Purchase patterns show parents often first buy a more affordable digital piano for their children and then upgrade to an acoustic if their child shows promise. The millennial generation, unsurprisingly, just likes digital. According to Euromonitor International, electric instruments make up over 40 per cent of Canadian instrument sales, while acoustic pianos and organs account for less than seven per cent.