The Guitar Amplifier The guitar amplifier is, put most simply, an electronic amplifier that can pick up the signal from a guitar—be it electric, bass or acoustic—and strengthen that through loudspeakers in order for the audience to experience the instruments better. However, especially nowadays, guitar amps can, and are often expected to do, more than just amplify a sound. Their construction allows them to modify the very timbre of an instrument and add several electronic effects. Although it sometimes isn’t recognised for it, guitar amplifiers have actually helped to shape and propel an incredibly large part of what we know as music today.
Historical and cultural development All of this, however, could not come without the often forgotten, century-old history and development of this technology. The first electronic amplifiers weren’t actually meant for electric guitars. Rather, because AM radios needed a way to be louder without the tedious use of carbon microphones in around 1905, the first ever electric amplifiers came about as early as 1912, based off the likes of Lee De Forest’s 1906 invention of the Audion, an electronic amplifying vacuum tube. From there, inventors consistently built upon what they knew of amplifying sound and the idea of utilising it for musical instruments—including guitars—was no longer so foreign. They essentially became amplified the moment electric amplifiers were born, since many musicians had been searching for a way to make their instruments louder, although there is debate on who exactly invented the first instrument amplifiers. By the 1930s, many different variations of the guitar amplifier were being developed. Despite early designs of amps being made predominantly for acoustic guitars, electric amplification became widely popularised for guitars in the 30s and 40s, which saw a craze for Hawaiian music and, consequently, the amplified lap steel Hawaiian guitar, which is sometimes considered to be the first instrument to be uniquely created by amplification. The end of World War II also saw the flourishment of instrument amplifications, leading us into the 50s and 60s, where most people will argue guitar amps had the most significant effect on music today. The electric guitar may well be the icon and have characterised the essence of rock ‘n’ roll—one of, if not the most, significant genres of Western popular music of the 20th century—but, truthfully, it would not have been the same without amplifiers. After hearing the concerns of electric guitar players being flushed out by the sounds of their bassist, drummer and vocalist counterparts, Clarence "Leo" Fender released the first commercially available, high-powered valve guitar amps in the spring of 1946. These tweed-covered, “Woodie” amps, the original Princeton, Professional and Model 26, were essentially what drove such a revolution in music history and most amps that followed were only trying to emulate that classic Fender sound, to varying degrees of success. In 1965, the music industry saw the rise of Marshall and their game-changing Plexis amplifier. This particular amp essentially defined the very sound of rock ‘n’ roll from the 60s and onwards. While Marshall and Fender dominated the scene during this time period, it was not until after the innovative 1970s that the first true three-channel tube amplifier was released. Steven Fryette’s Pitbull Classic was yet another revolutionary invention for not just the rock ‘n’ roll scene, but its ability to switch between a clean sound, a crunchy rhythm sound, and a soaring lead sound all-in-one meant that amplifiers would find their place in other genres with ease. This invention, and those that built upon it after, opened the doors for what we know as music to this very day.
Scientific development In the 1920s, it was very hard for a musician to find an amplifier. The first amplifiers and speakers could only be powered with large batteries, making them heavy and hard to carry around, as well as having a limited frequency range and low acoustic output. Engineers then developed the first loud and powerful amplifier and speaker for public address systems and movie theatres, though they were large and very expensive and were not suited to musicians at all. In 1927, smaller, portable PA systems and guitar combo amplifiers were developed and could be plugged into a regular wall socket. Early amplifiers had a single volume control and one or two input jackets, a field coil speaker and thin wooden cabinets. There were no tone controls or even an on and off switch. Up until the 1960s, most live pop bands used small combo 30 to 60-watt valve amps. These amps were poorly made and the distorted sound that they created is now considered to be a defining characteristic of typical rock music. Compared to a single string plucked on a clean acoustic guitar, a steel string guitar with amplified distortion is much thicker and mixed with discordant harmonics.
Explanation/demonstration of physical science The simple purpose of an amplifier is to receive a small electrical signal and enlarge it. Amplifiers work like a reverse microphone—they take electrical energy and transform it into kinetic energy, then, once again, into sound energy. To do this, amps use an alternating current source. Inside, a cone piece vibrates. The coil wire is tightly wound around the base of the cone and allows an electric current to pass through. This coil sits inside a cylindrical magnet, acting like a solenoid and producing its own magnetic field—except, in a speaker, the electric current is rapidly changing direction. The coil moves backwards and forwards as it is alternately repelled and attracted to the base of the cylindrical magnet. The cone of the amp, called the diaphragm, vibrates as the coil moves, causing the air to vibrate too, and produces the sound. You can change the strength of an electromagnet's magnetic field by varying the electrical current that passes through the wires wrapped around it.
Discussion of genre/styles/musical characteristics As mentioned earlier, rock ‘n’ roll dominated the Western music culture in the 20th century—Jimi Hendrix, Elvis Presley, The Beatles are just a few legendary artists who came out from this genre and continue to be household names even today— and while the guitar amplifier arguably had the most visible effect on this style of music, the sounds that it was capable of varied greatly, and that is the characteristic of this piece of technology that really made it so versatile and popular to this day. Distortion and overdrive were and are incredibly popular ways to alter the quality of electric guitars through amplifiers, creating that compressed sound often described as "gritty,” “fuzzy” and "dirty." It is an added feature found on most guitar amps that are not available on bass or keyboard amplifiers. Tube guitar amplifiers create distortion using several methods including, pre-distortion equalization, power-tube distortion and guitar speaker distortion. This is associated predominantly with metal and harder styles of rock. However, other genres and styles of music certainly are not completely foreign to the use of distortion effects, such as country star Marty Robbin’s 1961 single, Don’t Worry. Another musical characteristic of amps that is extremely popular even today is reverberation—the persistence of a noise after it is produced, creating an echo-like effect. Although reverb is not limited to just guitars, it is an important and distinctive trait of amplifiers to have a reverb option and give guitarists a bright-sounding and resonating effect. By recreating the acoustics of naturally resonant spaces, such as hallways and cathedrals, reverb on guitars allow for a much grander experience for the listener, and, perhaps, the most rewarding part about this effect is how versatile it is in terms of where it can commonly be found in different genres or styles of music. Other important musical characteristics often found in amps are vibrato, tremolo, echo and feedback. These styles can be found in virtually any genre, depending on the type of guitar used, such as electric, acoustic or bass, and the musical direction that the artist is going for.
Implications for musicians Which, of course, leads us to our last point—how it can be used by musicians now and in the future. The main idea that we hope has really gotten across to you today is how truly versatile the guitar amplifier is. Its design and construction allows the musician to tweak many different aspects of the sound simultaneously to achieve a unique combination of the effects mentioned previously (and more) and create a use for the guitar that is specific to the genre or style of music in mind. Amplifiers cater to the needs of not only electric guitars—as you may commonly associate them with—but acoustic, bass, and other guitars too. It also grants musicians the freedom to experiment with new sounds and expand and go beyond their imaginations, which, ultimately, is all music ever tries to do. Furthermore, due to the amount control guitarists have over their sound, it is common for other instruments, such as keyboards and synthesizers, to run through a guitar amplifier. Guitar amps can add tonal coloration, roll off unwanted high frequencies, and add overdrive and distortion. The controls allow a much richer sound to be created as opposed to a regular PA system. As of right now, guitar amps are almost always present on the stages of popular (and even more experimental) artists and bands, as well as in the studio. It is a staple in many musicians’ artillery of instruments, allowing guitarists to have the spotlight that they deserve amongst their counterparts. Some drawbacks, however, include the parameter limitations and how there is relatively more equipment to haul around than, say, direct input into a PA. In the future, perhaps the concept and technology of guitar amps can be condensed into a phone application that can be directly connected to a speaker system, significantly decreasing the hassle involved with setting up and transporting them from venue to venue. Nonetheless, many people—especially purists—will always prefer analogue technology over that of digital.
Classical Gas – Analysis [Structure] This is the basic structure of the excerpt which we will be referring to regularly, and here you can see that it is in ternary form, with the exception of Section A, which acts as an introduction to the song. [Duration – tempo] The tempo of the entire song is extremely quick, especially due to the fact that most of the melody is played in quavers. Section A begins at 146bpm and changes to 200bpm at 2:58, while sections B1, C and B2 are consistently 180bpm. [Duration – phrasing] The song is mostly irregularly phrased, because though it does follow a general pattern it is very loose and free in that manner. It is in 4/4 for majority of the excerpt with the exceptions of the end of Section A—in which there is no time signature—and sections B1 and B2, where it is 5/4 for one bar. [Duration – rhythm] A defining characteristic of Classical Gas is that it extremely syncopated. Section A also shows 3 different rhythms in each hand, as seen in these diagrams. The right hand strums Rhythm 1 at 2:40 for 2 measures, Rhythm 2 for five measures and then Rhythm 3 at 2:50, before returning to Rhythm 1 at 2:58 at an increased tempo. Meanwhile, the left hand drums Rhythm 1 at 2:40 using string slaps in beats 1 – 2 and thumping in beats 3 – 4, Rhythm 2 at 2:50 and finally back to Rhythm 1 at 2:58. [Dynamics and expressive techniques – dynamics] In terms of dynamics, Section A is shown to be forte throughout, before it crescendos into a fortissimo. Section B1 begins in mezzo-forte, but during the repeated arpeggio at 4:58, it becomes mezzo-piano. The next change in dynamic is heard in Section B2, which is begun in piano. However, there is a crescendo at the end of the section and excerpt. [Dynamics and expressive techniques – expressive techniques] In Section A, there is heavy use of artificial harmonics, string slaps, thumping, strumming and muffling, as well as staccato and marcato throughout, as seen in the score here. It does, however become mostly legato towards the end of Section B1 and B2, as well as throughout Section C. Classical Gas predominantly uses plucking but does not shy away from strumming as a means to accentuate the notes. The body of the guitar also doubles as a drum. In addition, hammer on and pull offs are extremely prominent throughout the piece. The guitar amp emphasises all of these expressive techniques in the context of a live audience and highlights how versatile it is.
Star Spangled Banner – Analysis The structure of the song is of ABACD form which is section A followed by B, A, C, etc. With that way that Hendrix plays, the structure may seem unclear, however it is there. Section B is a break section in which Hendrix incorporates his style of playing, straying from the original structure of Star Spangled Banner.
In regards to dynamics, the overall piece is relatively loud consisting of sections that are either forte or fortissimo. In sections, there are several decrescendos in certain parts, however, the levels ultimately stay in forte.
Hendrix's style is quite dependent on his use of performance techniques. Throughout this piece, a range of techniques are used. The piece is majorly picked, expressing individual notes as opposed to strumming chords. Vibrato is expressed throughout each section, majorly contributing to the overall sound of the piece. Hendrix also incorporates bending, sliding, short trills and muting in the performance.
The performing media involves an electric guitar that is played with the added effects, such as distortion, from a guitar amplifier. The distorted effects give a harsh, unpleasant tone to the piece. However, when picking, each individual note is expressed clearly. In context (which was 1960s America), there was a war going on and so Hendrix incorporated this idea into the performance. Certain notes that were held out were piercing/screechy which mimicked the sounds of screaming or crying. Some held out notes even resembled that of bombs dropping. During section B, the performance becomes more intense as blunt, muted strumming is introduced. There are quick changes in distorted notes. Overall the piece created a sombre and distressed atmosphere. The performance would not be the same without the use of a guitar amplifier and its effects.
Summary In today’s society, majority of live music is amplified to fit the context of a physically present audience and we often take for granted all that guitar amps have done to progress the music industry. We forget that much of what we hear “live” is almost always accentuated and shaped by amps. Consequently, there is the sense that the speaker becomes the very instrument. Its versatility, rich history and prominence throughout many genres of music is what makes the guitar amp so important to musicians and audiences alike.