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How a Guitar Works - from Wood to Electric
Coming of age
by Virginia Fair
“Growing older is a community project. We’re all in it together.” This is a bon mot my cousin gives his kids and grandkids when they make remarks about his age. My palliative vision of aging is one of travel - we’re all trekking down the same long, meandering path. Some are ahead of me, some are behind but none-the-less, we’re all moving on. Community project, or long and winding road, neither of us is saying aging is easy, but we take comfort where we find it, and just as their music sustained me through my youth, so now do I take equal comfort in the fact that Paul and Ringo (alas not John and George) are just around the bend ahead of me on that path. Mick and Keith are up there too. (If you need last names here, you are either way behind me, or ahem, way ahead).
To keep current on “road” conditions I rely on my favorite radio station’s birthday reports. Each morning as I drive to work I find out whose special day it is, and whether they’re up ahead or behind. I found the road a bit crowded at the end of May. On the 24th, it was Bob Dylan. “Wow!” I marveled, “ 69”! On the 26th, I found out Levon Helm of The Band was just ahead of Bob at mile marker 70! And on May 26th behind them both at 65, but mercifully still ahead of me, was John Fogarty of Creedence Clearwater!
As a rule, the station observes each of these days with a block of the birthday boy’s songs (or birthday girl’s - Marianne Faithful and Patty Smith both turned 63 on December 23 and 30 respectively). But it was a bit of musical history on Bob Dylan’s b-day that sent me digging for the information for this article. Initially a folk singer specializing in protest songs, Dylan showed up with an electric guitar and found himself being booed off the stage. He had broken the ultimate folkie rule: “Acoustic guitars only”. I guess they feared he’d turned rocker on them; but they would learn as time went on, as we all have, that Mr. Dylan was not one on whom labels would stick.
Trying to figure out why this constituted such a big deal led me to the realization that I really didn’t know that much about an instrument I’d been hearing day in and day out for over….well, let’s l just say, a heck of a lot of years.
 Up until the 1930’s all guitars were acoustic. Generally speaking, the design was rather uniform: Constructed of wood, six strings attached to posts at the head, wrapped around the tuning pegs, and stretched down the neck, past the hole in the middle of the body and connected to the guitar body just below it. But if we look a little closer we will see that horizontal strips of metal span the neck at uniform intervals. A Classical acoustic guitar has nineteen and an electrical guitar twenty one to twenty four.
(Number-phobes like me might want to skip rest of this paragraph, or at the very least, pause and take a deep calming breath!)
These strips are called frets, and a precise mathematical ratio governs their spacing, with every twelve frets spanning an octave. Starting at the top, the interval between each neighboring fret is considered a half step up on the chromatic scale. (keep breathing) The tuning pegs are rotated to adjust the tension of the strings, and once tuned; pressing the string back to the fretboard at any particular fret shortens the vibrating length of the string and raises the pitch.
While instrumental (no pun intended) the strings are only half the story when it comes to assigning responsibility for the sound we identify as “the guitar.” For a full explanation we need to look at the guitar body. The body of an acoustic guitar is hollow and made of wood. The front is the soundboard and as the name implies, is the other major player in “the music.”In the middle of the soundboard we find the soundhole, and just beneath it, the bridge assembly which anchors the lower ends of the six strings. Within the bridge is the saddle against which the strings rest. When a string is plucked, it sets up a vibration which travels through the saddle to the bridge to the soundboard. At this point the entire soundboard vibrates and the guitar body becomes a hollow soundbox amplifying the vibrations of the strings thus producing the distinctive guitar sound.
But back to the strings; originally made from animal gut, today’s strings are largely nylon or steel. How long are they? An open string, one that has not been pressed to a fret, measures 24 to 26 inches from the nut at the top to the saddle. But if the string is pressed to the fret, it is shortened and the vibration changes the frequency that ultimately resounds in the soundbox. Another thing to consider is the tension on the strings. This is determined by the tuning peg. How tightly it is wound determines how much it can vibrate; and so does the weight of the strings which increases from left to right, from the thread- like first string to the thickly-wound sixth.
The wood used in the guitar’s construction has an effect as well, although it has more of a bearing on acoustic than electric. Alder and poplar are good for producing bright, well-rounded tones. Ash is similar but can reach more defined highs and lows while mahogany is preferred by guitarists looking for dark bass tones. Maple gives very bright tones, but has the disadvantage of being heaver in weight.
There’s no disputing that the acoustic guitar is a very capable instrument still used by countless musicians but problems began to arise in the 1930’s when jazz guitarists found that their music was being drowned out by the horns and drums that played such a big role in the Big Band era. Many individuals began tinkering around looking for a way to amplify the sound electrically. In a very rudimentary baby step, Les Paul, already an accomplished acoustic guitarist experimented with attaching a microphone to an acoustic guitar.
Eventually, electromagnetism provided the answer. Sensors called pickups were mounted on different points of the guitar. Consisting of a magnet wrapped in coil, the job of the pickup is to register the vibrations of the strings. When the guitar is strummed, the movement of the strings generates a very small electrical current in the pickup, which is then passed through a cable and on to an amplifier where it is boosted to a strength sufficient to drive a speaker.
 As so often happens, one change necessitates another, and the next alteration was to the guitar body. Although the hollow body offers a functionally resonating space in acoustic music, it also could produce unwanted feedback distortions and overtones in amplified music. Again, a flurry of experimentation filled the air, and In 1932 The Rickenbacker Company, introduced The Frying Pan, so named for its shape. Made of cast aluminum, and played flat in the lap, it was also called The Pancake Guitar. In 1936, the Slingerland Company offered a solid body wooden guitar, and soon afterward, in 1940, still at work in his quest, Les Paul mounted strings and pickups on a solid block of pine, and fittingly enough dubbed it The Log.
But the foundation for today’s electric guitars was laid in 1946 when a radio repairman named Leo Fender designed a solid body guitar with a single magnetic pickup which he named the Esquire. When he added a second pickup, he differentiated models by calling this the Broadcaster , later changed to Telecaster when it was learned there was already a drum set marketed as Broadkaster, and the race was on! In 1952, the Gibson Guitar company countered with an electric model endorsed by Les Paul, and in 1954, Fender introduced its deluxe model, the Stratocaster, which would go on to become a classic. Gibson went on to create the Les Paul line, thus immortalizing the pioneer’s name.
What I find particularly fascinating is the fact that the electric guitar, despite all the attention and spotlight focused on it is, in itself, completely passive. It doesn’t even need to be plugged in! The real star here is the amplifier. It takes the guitar’s bare, unamplified signal and pumps it up on its way to the speaker. But my, oh my, the things it can do to that little baby signal on its way to the speaker. Remember distortion and feedback, two of the reasons for going from hollow to solid body? Well, rock music sees them as guitar effects and relies on the amplifier to put it all together.
Distortion is the product of a signal that is too powerful for the amplifier’s circuitry. A guitarist who desires a buzzing, distorted, extremely loud sound would choose an amplifier that lets him control that distortion. Major names include Pete Townsend of The Who , one of the first to embrace distortion in the 60’s, by Jimmy Page of Led Zeppelin and AC/DC’s Angus Young in the 70’s, and Guns and Roses’ Slash in the 80’s and 90’s as well as countless bands playing all over the world in the largest venues as well as the dinkiest dives.
For feedback, guitarists desiring it can create a feedback loop. This occurs when the sound coming out of the amplifier is so loud that it causes the guitar strings to vibrate. By hitting a note on his guitar, the player can set up a mobius strip of indefinitely vibrating notes. Eddie Van Halen of Van Halen is fond of these as was Jimi Hendrix.
 No discussion of guitar effects would be complete without a mention of the wah wah pedal. The name is actually self-explanatory, you step on a pedal to produce the voice-like Wah Wah. Engineers stumbled upon the phenomenon accidentally while replacing the mid-range-boost vacuum tube circuitry of an amplifiers and replacing it with a transistorized solid state one. In the process they altered the tone of the signal and were puzzled to hear the afore-mentioned wah-wah. Recognizing that they had a good thing, they looked for ways recreate the sound and came up with a foot pedal that when inserted between the guitar and the amplifier could nudge the peak response filter up and down in frequency to create the sound. Wah Wah became such a big part of music that it even got its own song, Wah Wah by George Harrison. Eric Clapton also stepped on the pedal in the old Cream song “White Room.”
So basically the recipe boils down to three main ingredients – the guitar player, the guitar and the amplifier. And as any good cook will tell you, spices add the personalizing touch. So bring on the wah wah, turn up the distortion, and let the feedback begin!
And now I must end the article, due to extreme shock. As I was putting on the finishing touches, the radio just caught my attention with the news that tomorrow, July 7, is Ringo Starr’s birthday. He will be 70. Ringo? Ringo Starr will be 70? Say it isn’t so!
By the way, although Kintronics doesn’t sell Fender guitars, we do carry the Fender Passport series of portable PA systems. Anyone in need of one can call us for information. 1-914-944-3425 or 1-800-431-1658.
[PRINTER FRIENDLY VERSION]
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Published by
Bob Mesnik
Copyright © 2010 Kintronics, Inc.. All rights reserved.
For more information, please contact us 1-800-431-1658 or 914-944-3425 (outside the USA) or by email infohome at kintronics.com
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