The Chemistry of a Piano

Introduction

The piano is an instrument, and for an instrument to work, especially as effectively as a piano, the materials used in the production need to reviewed. I chose it because I love to play the piano. Since I play it, it affects my life by the music it produces.

Composition of ...There are many types of woods used in the piano, which are maple, spruce, basswood, pearwood, and ebony (which may not be used in pianos today). The part of the tree trunk used is the heartwood, for it has less moisture and is harder than sapwood. Heartwood is composed of sugars (C6O12H6), dead xylem cells, dyes, oils, resins, phenols, and terpenes. Ebony, however, is a little bit different, for it has a higher silica content (SiO2). This makes the ebony more dense than water. Also, the white keys were originally made of ivory, typically from elephants. Ivory is primarily made of dentin and cementum. Dentin is made of 70% inorganic material, hydroxylapatite [Ca5(PO4)3(OH)] and calcium phosphate [Ca3O8P2], along with 30% of collagen [C2H5NOC5H9NOC5H10NO2]. Cementum is made of 45% of inorganic material, which is mainly hydroxylapatite along with a little bit of calcium. It is also made of 33% organic material and 22% water. The copper wire is made of, well, copper. Carbon steel is an alloy of less than 1% of carbon and around 99% of iron. The cast iron plate used in pianos is made of primarily iron.

Main Chemicals, Compounds, Components

Piano Keys:

Ivory was used for piano keys way before elephants, the main source for ivory, started to become endangered. As mentioned under the Composition of Pianos, it is comprised of dentin and cementum. Ivory was, and still is, desired by pianists because of its ability to be less likely to stick to their fingers if playing a difficult piece. Also, since ivory absorbs sweat, the keys could have a better feel. Nowadays, plastics are used for their durability and their inexpensive price. Yamaha has even produced a plastic called Ivorite, which supposedly mimics ivory.

Ebony or pearwood is customarily used for the sharp keys. They are both quality hardwoods and are very durable. Sometimes, in cheaper pianos, woods with less quality are used, and they would then have a very thick coat of lacquer or plastic applied to it to hide the lack of quality. Again, the heartwood of the ebony or pearwood trees are used in the making of the sharps.

Piano Strings:

The main wire used for the piano strings is high carbon steel. It is created through the melting of iron and carbon together. When carbon is added to liquid iron, the carbon atoms go to attach themselves to the iron atoms. The iron atoms were in a lattice structure before the carbon was added, so the carbon atoms go to lodge in between all the iron atoms, creating more strength in the metal. High carbon steel is very strong; however, if too much carbon was in the steel, it wouldn’t be ductile enough to be shaped into a wire. The perfect amount of strength and flexibility is why high carbon steel is used in pianos today.

Copper wires are also used to cover the carbon steel wires used for lower pitches. This is for the lower notes to be able to vibrate slower. Copper wires are made through the processes of drawing and annealing. Drawing is the process of making the copper have a smaller diameter by putting it in a die, a cylindrical part that has a cone-like shape cut inside of it. One side of the die is the same diameter of the copper rod, and the other side has a smaller diameter. This way, as the copper rod goes through the die, it shrinks and becomes longer, and this is done by putting the copper rod in smaller and smaller dies until it achieves the desired diameter. Once the drawing process is done, the copper is brittle. To fix this, the copper rod goes through the annealing process, which helps the copper reclaim its flexibility. Previously, in the drawing process, no heat was used. Now, with annealing, the rod goes in an electrical furnace which is specifically designed for annealing. As heat is applied, the copper crystallizes and becomes a softer solid.

Chemistry's Role

*Ivory and ebony are both naturally occurring, albeit in an elephant or a tree. The chemistry and the chemical processes inside the living things causes the ivory or the ebony to be created. Ivory has a similar structure to bone. However, ivory doesn’t have blood vessels, and this makes it more dense. Similarly, ebony is a hardwood, and as xylem cells die and the tree grows, the heartwood part of the tree trunk is made. Due to the higher content of silica in ebony, it also is very dense. Dense enough that it sinks in water.

*High carbon steel is an alloy, and alloys are part of chemistry. An alloy is created when two or more elements, at least one being a metal, are melted together to change their chemical and physical properties. Iron alone is strong, but with the added carbon, it becomes stronger. The process of drawing the copper wire causes it to become brittle, unlike the copper wires we have come to know and love. When heat is added to it through the annealing process, the copper can crystallize and become malleable enough to be put in coils around the high carbon steel on the left of the piano.

*The end product of the piano is man-made. There are no real chemical processes in the actual producing of it, but everything inside of the piano has had a chemical process or a lot of chemical processes to help create the material that makes up the musically inclined piano.

Background Research

Other string instruments, like the harp, are mentioned even back in the Bible. The harpsichord became the most popular instrument in the 17th century, one of the first instruments with keys and strings. Next came the dulcimer and the clavichord, with the latter leading to the pianoforte, long for piano.

Bartolomeo di Francesco Cristofori, a harpsichord maker, is credited with creating the piano by 1700. The difference between the soft clavichord and the loud harpsichord with the piano was the range of sound that the instrument could be. The piano could, and can be, as soft or as loud as needs be. As improvements continued, the structure of the modern piano came to be by the mid-nineteenth century.

Although the piano is definitely more physics than chemistry, there is still chemistry in it.

Resources

http://www.madehow.com/Volume-3/Piano.html

*history

*a little bit of what it’s made of

*list of raw materials

*process of how it’s made

http://www.madehow.com/knowledge/Piano.html

*history

*how sound is made

*components (strings, wood, etc)

http://www.frederickcollection.org/works.html

*variables on sound

*different parts of piano

*detailed descriptions the how

http://www.ptg.org/userfiles/file/learningCenter/Piano_Science.pdf

*how pianos work

*parts of the piano and their definitions

http://hyperphysics.phy-astr.gsu.edu/hbase/music/pianof.html

*the frequency of sound from piano

*some history

*the number of strings per key

*a little on how it works

http://www.ehow.com/facts_5718809_chemical-formula-steel_.html

*amount of carbon and iron in high-carbon steel

http://www.freestatepianoworks.com/uploads/2/6/1/4/2614522/worn_sharp_keys.pdf

*ebony keys

http://www.pianonoise.com/Article.Piano.htm

*how a piano works

*a detailed description of everything inside the piano

https://en.wikipedia.org/wiki/Carbon_steel#Forging_temperature_of_steel

*how carbon steel is formed

http://www.ehow.com/how-does_5381659_copper-wire-made.html

*how copper is made into wires

http://www.innovateus.net/innopedia/what-ivory

*the different types of ivory

*commercial uses of ivory (like piano keys)

*properties of ivory

http://www.uniclectica.com/conserva/ivory1.html

*composition of elephant ivory

https://en.wikipedia.org/wiki/Dentin

*composition of dentin

http://www.reciprocalnet.org/recipnet/showsamplebasic.jsp?sampleId=27344779

*chemical formula for collagen

http://pubchem.ncbi.nlm.nih.gov/compound/Calcium_phosphate

*chemical formula for calcium phosphate

https://en.wikipedia.org/wiki/Hydroxylapatite

*chemical formula for hydroxylapatite

http://northernwoodlands.org/articles/article/what_is_the_difference_between_sapwood_and_heartwood

*composition of heartwood

http://v5.books.elsevier.com/bookscat/samples/9780723431817/9780723431817.pdf

*talks about cementum and what’s inside of it

https://anamazingmachine.wordpress.com/piano-resources/

*the pros of ivory keys

http://www.ehow.com/about_6638014_atomic-structure-steel.html

*the atomic structure of carbon steel

About the Author

Linda Erekson currently attends Billings Senior High as a junior. She has been playing the piano since late February of 2009. She also participates in choir. She excels in math and hopes to become an engineer. Volleyball is a hobby; however, cross country and track is where it’s at. Academic Team, or nerd squad for short, is one of the clubs she participates in, along with STEM Society, Interact, and Tech Club.