I went to Seat­tle recently and while there I took in the Expe­ri­ence Music Project. One of the most inter­est­ing exhibits was the his­tory of the gui­tar. But of par­tic­u­lar inter­est to me was the dis­play of early elec­tric guitars.

Mod­ern music has much to owe the elec­tric gui­tar. Elec­tric gui­tars brought with them the oppor­tu­nity to mod­ify a sound in ways pre­vi­ously unimag­in­able. Once the sound waves were con­verted to an elec­tri­cal sig­nal, that sig­nal could be altered in a man­ner that would be imprac­ti­cal, or impos­si­ble if one were work­ing on the sound waves alone.

If you would like to know more about the his­tory of elec­tric gui­tars then you can read about them on answers​.com as they do a much bet­ter job of relat­ing the his­tory than I intend to go into here. My inter­est lies in how elec­tri­fi­ca­tion changed the face of music.

Every instru­ment has an ampli­fier of sort. Some part of any instru­ment takes the vibra­tion of the sig­nal gen­er­a­tor and ampli­fies the amount of air it moves so as to make those vibra­tions more audi­ble. In many stringed instru­ments it hap­pens to be a box with some sound holes cut into it. Even now, most elec­tric gui­tars have a solid body and are very quiet when not plugged in as the gui­tar body make a lousy resonator.

The ampli­fy­ing ele­ment of an instru­ment is often respon­si­ble for the tim­bre of that instru­ment. It’s what makes a French horn sound dif­fer­ent from a trom­bone even though both cover roughly the same range of fun­da­men­tal frequencies.

The con­fig­u­ra­tion and mate­r­ial of the res­onator empha­sises or atten­u­ates dif­fer­ent har­monic fre­quen­cies so the final com­plex wave­form pro­duced is of a par­tic­u­lar char­ac­ter, dis­tin­guish­able from one instru­ment to the next.

Early gui­tar effects were the result of lim­i­ta­tions in the ampli­fier to faith­fully repro­duce a sound wave. In the six­ties some musi­cians began boost­ing the sig­nal from the gui­tar to the limit of the ampli­fier. This was accom­plished by using pre-amplifiers to over­drive the gain or by sim­ply rais­ing the vol­ume on the amp until it started to distort.

High gain sig­nals would sat­u­rate the valves caus­ing the top and bot­tom of the sig­nal wave to be clipped off. In other words the sig­nal ampli­tude would actu­ally go higher if it were allowed but lim­i­ta­tions of the elec­tron­ics, or even phys­i­cal lim­i­ta­tions of the speaker being extended or retracted com­pletely, dis­al­lowed this. What would nor­mally be a sine-wave ends up look­ing more like a square-wave (A sim­pli­fi­ca­tion, I know. Look here and here for a more in depth treatment).

Another way musi­cians would change the sound com­ing from the ampli­fier would be to tear, cut, or punch holes in, the paper cone of the speaker. This would give the gui­tar a fuzzy qual­ity, a sound that was later pack­aged up in a stomp box sav­ing count­less speak­ers from such unspeak­able horrors.

With the advent of the tran­sis­tor and its sub­se­quent use in pre-amps and amps, a harder clip­ping qual­ity was brought to over­drive dis­tor­tion as the tran­sis­tor had dif­fer­ent sat­u­ra­tion char­ac­ter­is­tics than vac­uum tubes. The sharp edge of its clip­ping meant that the result­ing sig­nal con­tained more of the higher level har­mon­ics than tubes which then trans­lates to a ‘colder’, sound.

In any other appli­ca­tion all this would be con­sid­ered a bad thing. For some rea­son hav­ing an ampli­fier that doesn’t accu­rately repro­duce the sig­nal it is being fed became a desir­able thing. The col­oration and tone that was intro­duced into the sig­nal by the way in which ampli­fiers dis­torted the sig­nal rep­re­sented a shift in what an amplifier’s pur­pose was to the elec­tric gui­tar. In effect, the ampli­fier became part of the instru­ment in a way that tran­scended mere sound­board sta­tus. Given the nature of the guitar/amplifier rela­tion­ship you could now change the tim­bre of the instru­ment at will just by choos­ing another ampli­fier or by turn­ing a dial. This abil­ity was of mon­u­men­tal impor­tance in the his­tory of music. Never before was there such ease and flex­i­bil­ity in choos­ing the tone of an instrument.

To be sure, dis­tor­tion in ampli­fiers was an issue long before it was put to musi­cal use. See­ing as gui­tars were first elec­tri­fied in the 30’s and dis­tor­tion effects were being used in music dur­ing the 60’s one may pos­tu­late that it was the change in musi­cal styles that informed the lis­ten­ers as how they should per­ceive this dis­tor­tion. Rock-and-Roll emerged in the 50’s at a time when the elec­tric gui­tar was first mass mar­keted. Being the musi­cal style that began to cap­i­talise on these effects in the 60’s it only seems fair to place blame on the mis­cre­ant youth. The com­bi­na­tion of rebel­lious music, and now a viable instru­ment that can be made really loud, were the per­fect con­di­tions for dis­tor­tion to be used pro­duc­tively. Rock and elec­tric gui­tars go hand-in-hand and in part this match is enabled by the effects pedal. Noth­ing says “I’m rebelling” quite like the harsh tones of an amp that is being used the “wrong” way. It’s cer­tainly noth­ing that Benny Good­man would approve of.

It seems to me as though the quest for nov­elty exploded in the 60’s and to stand out above those who employed gui­tar effects you had to do ever increas­ingly bizarre things to your sound. It was a bless­ing that the gui­tar was elec­tri­fied as you could now inter­ject devices into the sig­nal flow that could mod­ify the sound in wild ways. The sound of the gui­tar did not resem­ble what it was and it was never going back.

New gen­res of music would rise up as musi­cians incor­po­rate new effects into their play­ing. The effect helps define these gen­res as play­ing style adapts to max­imise or rev­o­lu­tionise the effect and the effect itself becomes part of the sig­na­ture of that music. Con­sider the Wah-Wah and its dis­tinc­tive use by Jimi Hen­drix and later adop­tion by funk and soul musi­cians, psy­che­delic rock and funk wouldn’t be the same with­out it. The vari­ety of musi­cal gen­res that have emerged out of, and since, Rock-and-Roll are nearly always inex­tri­ca­bly tied to the sound the gui­tarist was try­ing to produce.

Another form of dis­tor­tion nor­mally con­sid­ered detri­men­tal in sound rein­force­ment has become a sta­ple of Rock musi­cians. Con­trolled feed­back became a tool in the musician’s reper­toire also dur­ing the 60’s by such notable bands as: The Bea­t­les, The Monks, The Who, The Kinks, and of course Jimi Hen­drix. With feed­back another means of play­ing the gui­tar was born, one that would have been unob­tain­able with­out elec­tric guitars.

There are so many effects now­days pack­aged into stomp­boxes that rarely do we see pro­fes­sional gui­tarist with­out them. The cat is out of the bag and you would be hard pressed to put it back in. Once gui­tarists are given the choice of tweak­ing their sound they often will not do with­out. For all the ben­e­fits to sculpt­ing your sound there is a down­side too: reliance on effects can mask bad play­ing, pre­vent­ing you from devel­op­ing as a player. To that end I wouldn’t rec­om­mend start­ing a kid off with an elec­tric gui­tar and a ped­al­board full of stomp­boxes. They may not progress past mak­ing cool noises.

The next step in sound pro­cess­ing was to take the sig­nal which was mod­i­fied by elec­tri­cal com­po­nents and turn it to dig­i­tal infor­ma­tion. Now sound is unhar­nessed from the hard­ware and exists purely as a math­e­mat­i­cal con­struct. As such, the wave may be changed through oper­a­tions in any way that you could math­e­mat­i­cally describe. With the cost of micro­proces­sors hav­ing dra­mat­i­cally fallen and a sig­nif­i­cant his­tory of Dig­i­tal Sig­nal Pro­cess­ing under our belt, nearly any sort of wave shap­ing you could pos­si­bly want is avail­able. There are lim­its based on dig­i­tal to ana­log con­ver­sion hard­ware, proces­sor speed, and what you can math­e­mat­i­cally define, but the plethora of dig­i­tal effects out today, and those that are pos­si­ble but as of yet unre­alised, we will have no short­age of novel tim­bres to influ­ence our playing.

Tags: Creativity, Guitar, Guitar Effects, History, Music Technology, Popular Music, Rock

This entry was posted on Tuesday, June 24th, 2008 at 9:24 pm and is filed under Everything Else. You can follow any responses to this entry through the RSS 2.0 feed.