It’s a long road – with strings attached – from a troubadour’s “Greensleeves” to GWAR’s “Triumph of the Pig Children” and Jason Aldean’s “Old Boots, New Dirt.” But guitars made it happen. And that technology story is told in the Discovery Place touring exhibition “Guitar: The Instrument that Rocked the World,” which opens May 30.
It’s what HP Newquist, calls “stealth science”: using the popularity of the guitar to attract visitors curious about the science behind the six-string.
Newquist is executive director of the National Guitar Museum, which has had this exhibit on tour since 2011. Besides being the former editor-in-chief of Guitar magazine, he’s an award-winning author of science books who has worked in the artificial intelligence industry. Who better to explain the physics and technology of guitars?
Q. What’s the basic science behind the guitar?
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A. It’s the same as any stringed instruments. Sound waves are produced by vibrating a length of string. By stringing sixth lengths, each is capable of a a different frequency, tone and pitch.
Stretch a short rubber band and pluck it: You get a high-pitched bling. Use a bungee cord instead, and you get this long vibration that’s much lower. When you have a long string, you have lower vibration frequency. Shorten that length on a guitar by fretting and it vibrates faster, causing higher notes and pitches.The tuning of strings goes back to prehistory – tightening a vine or catgut to produce a pleasant sound. Over the years, tightening gears – tuning pegs – were created so you could adjust the string to the precise tone you wanted.
Q. Why does a guitar have six strings?
A. Instruments that came before it had different neck lengths and numbers of strings – as many as 14 strings. More strings means a more jangly sounds from more frequencies and more sound waves. In the late 1700s, when composers created Romantic classical music, guitars were used to produce melody lines. Guitars got stripped down: Six strings created a wide enough range of notes to choose from and was more pleasant to listen to.
Q. Stradivarius is the tech star of violin design. Is there one for the guitar?
A. Violins have been around a lot longer and cost a lot more. There are many noteworthy guitars, including several Stradivarius made, that are prized.
Physics makes guitars harder to make: There’s more physical pull on their strings that caused them to break down and self-destruct, more so than violins.
The sound is produced by the soundboard, the top face of the guitar. How much vibration can that top piece produce when the string is strummed? It’s a difficult engineering balance to create a soundboard thin enough to vibrate – but which can withstand as much as 200 pounds of pull from the strings attached to its end. In the exhibit, we have a scale so you can try to match 200 pounds of string pull. Most people can’t.
Q. What’s the trick to making this work: Instrument material or construction?
A. Construction. One of the first people to figure this out was Antonio Torres, of Spain. In the 1850s he actually made a guitar with a body of papier-mache, but he braced the top – putting thin strips of wood under it for support, to resist the pull of the strings. That guitar is considered one of the best of that era.
When tuned to tension, it pulls as much as 200 pounds at its base. Yet the top of the guitar is only as thick as a Popsicle stick. By bracing the inside, it created a guitar that can produce more sound yet not rip itself apart.
The modern acoustic guitar came about primarily because of C.F. Martin in the mid-1800s; his is today one of the oldest, continuously running family businesses in America. He came up with a form of bracing that allowed guitars to withstand the pull of steel springs, which vibrate at a much higher frequency and produce more sound. Before this, all strings were made of catgut – which doesn’t actually involve cats. It’s almost always sheep intestine.
Q. Of all the musical instruments, why did the guitar become electrified first?
A. The entire history of the guitar is about making a louder sound. In the early 1900s, it was a parlor instrument and probably more played by women. But when bands began to travel, trumpeters, keyboardists and vocalists could out- play or out-shout a guitar. Guitars became larger to get more sound from the soundboard, but in the ’20s and ’30s the guitar was still being drowned out.
The change came because of Hawaiian music, by far the most popular type of American music from 1915 until the beginning of World War II. It influenced everything. Touring bands played it and had someone playing the lap steel guitar. The leader of one such band, George Beauchamp, got tired of not hearing his own playing over the band’s. His experiments included building a cone into the soundboard – and this evolved into the Dobro.
That still wasn’t loud enough. But noting the growing popularity of electricity in America, he affixed two magnets to the body of his metal-stringed lap guitar. The magnets could pick up the steel strings’ vibrations, send them by wire into a radio and amplify what he was playing. It was the first-ever electric guitar.
We have one of the originals in the exhibit. It doesn’t look like a guitar; it looks like a frying pan – and that’s what it was called.
The magnets – pickups – changed the entire nature of music. There’s plastic put around them now, but every pickup for any stringed instrument still relies primarily on a magnet wrapped by copper wire. When a metal string passes over a magnet, it interrupts the magnetic field and creates a signal that’s transferred to the amplifier.
“Guitar: The Instrument that Rocked the World” runs May 30-Sept. 7 at Discovery Place, 301 N. Tryon St., Charlotte. The exhibit is included in regular admission ($15; $12 for ages 2-13 and 60 and older). It includes more than 60 instruments plus other artifacts and interactive displays. Hours: 9 a.m.-4 p.m. weekdays, 10 a.m.-6 p.m. Saturday, noon-5 p.m. Sunday. Details: 704-372-6261; www.discoveryplace.org.