Studio Sound: Synthetic Materials in Music Gear

A Tour of the Recording Studio

1The jazz band from Eastfield Middle School spent a Saturday recording at a community studio. Before the session, sound engineer Ms. Beatriz Nakamura gave the band a tour. She pointed out that almost every object in the room started as a natural resource. Some objects are made of natural materials, which are cleaned, cut, dried or woven without changing what substance they are. The top of an acoustic guitar is often a thin sheet of spruce wood, the rug under the drum set is wool, and an old pair of hand drums has heads made of calfskin.

2Many other objects are made of synthetic materials: new substances that people make through chemical processes. Nylon guitar strings and the soft foam panels on the walls usually start as crude oil or natural gas. At a chemical plant, small molecules made from these resources react and link into very long chains called polymers. Melted nylon is pushed through tiny holes to form strings. Foam forms when liquid ingredients react and puff up with gas bubbles. Vinyl, the plastic in records, is made from two resources: chlorine that comes from ordinary salt, and natural gas or oil.

3Not every synthetic material starts as oil. Celluloid, one of the first plastics, was invented in the 1800s. It is made by treating cellulose, the fiber in cotton and wood, with chemicals until it becomes a new, hard substance that can be shaped. Celluloid was used for guitar picks and to cover piano keys. Before that, many piano keys were covered with ivory from elephant tusks, and many picks were made from the shells of sea turtles. Plastic keys and picks helped lower the demand for these animal materials.

4Synthetic materials also bring costs. Making them uses resources and energy, and crude oil and natural gas are nonrenewable. Many plastics break down very slowly, so old foam panels and records often stay in landfills for a long time. Some studios now buy wall panels made from recycled plastic bottles or from natural fibers.

5Lior Mendoza, the band's guitarist, plays a classical guitar with nylon strings. His teacher still prefers gut strings, which are made from cleaned and twisted sheep intestines. Lior wondered which kind stays in tune better. Ms. Nakamura borrowed two guitars of the same model. She put gut strings on one and nylon strings on the other, tuned both with the same electronic tuner and left them in the studio's main room for five days. Each morning she wrote down the humidity, which is the amount of water vapor in the air, and counted how many of the six strings on each guitar had gone out of tune. Then she retuned them. Her results are in Table 1.