Explainer

Why Do Cellos Sound Lousy in Cold Weather?

The optimal climate for musical instruments.

Itzhak Perlman, Yo-Yo Ma, and Anthony McGill

Inauguration organizers admitted on Friday that while Yo-Yo Ma and his fellow musicians were playing live onstage at the ceremony last week, they weren’t miked; it was the sound of a pre-recorded performance that was heard in the crowd and around the world. The musicians explained that the temperature conditions would have ruined the sound. What are the optimal climatic conditions for playing an instrument?

Around 70 degrees, with 40 percent to 50 percent humidity. But instruments are more stressed by rapidly changing conditions than by extreme temperatures or moisture levels. Because heating systems warm air without adding moisture, the relative humidity is often as much as 30 percent to 40 percent lower indoors, even on a cold and dry day. When instruments made of wood move between environments of varying humidity, they absorb or expel moisture. The resulting expansion and contraction can crack the instrument. String instruments, such as violins and cellos, are particularly susceptible to cracking, because they are often made of two different types of wood (usually spruce and maple) that absorb moisture at different rates. Hide glue, the collagen-based sealant used to secure the pieces together, moderates the problem. It is weaker than synthetic glues and is likely to release the various parts before the wood cracks.

Less dramatic climatic changes can take instruments out of tune. Piano strings, made of a combination of steel and copper, expand and contract in response to temperature changes. Even the warmth of stage lights can affect a piano. For this reason, pianos are usually tuned just before a performance and left in place, but doing so in the outdoor din and clamor of Inauguration Day would have been tough. Modern violin strings are less susceptible to expanding and contracting, as they are made of a type of nylon rather than the traditional “gut,” or sheep intestine. However, the pegs that hold the strings do expand or contract in response to changes in humidity, loosening or tightening the strings.

In terms of absolute temperature tolerance, hide glue and varnish soften at around 120 degrees Fahrenheit, raising the risk that the instrument will become sticky and fall apart. And no instrument containing high moisture levels (such as the clarinet, which must be played with a moist reed) can be used at temperatures below freezing. As for string instruments, the minimum temperature would depend on the instrument’s storage history and age.

Both Yo-Yo Ma and Itzhak Perlman left their Stradivarius instruments at home on Inauguration Day, preferring to subject less-valuable pieces to the cold. (In a bit of irony, some scientists believe that a prolonged cold period is what gave the prized Stradivarius instruments, built around 1700, their unique sound.) But a cracked Stradivarius would not be the tragedy one might imagine. Of the 600 or so remaining instruments, almost all have experienced some form of trauma, ranging from poor storage to being thrown in a trash bin or crushed under the weight of a violin virtuoso. Repair is expensive but effective. And experts believe even the most mint Stradivarius pieces sound nothing like their original incarnations. Shortly after the instruments’ creation, finicky luthiers thinned the wood to generate a bolder, louder sound. Most modern musicians have also adjusted the neck angle and play with different bridge and bow types.

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Explainer thanks Stewart Pollens of The Violin Advisor.