Some time ago I wrote a piece for my Masters in Music on the development of extended performance techniques on the acoustic guitar, as it's my other 'job'. I thought I'd share an edited version here!...
What is the Article About?
This article aims to survey the development of the acoustic guitar’s specific and often ‘extended’ performance techniques in relation to popular musical works and will discuss to what extent these techniques have permeated Pop and popular music (the perceived differences are defined further in the essay) and key composers and performers within these boundaries. It is hoped that a new collective insight will be conflated through bibliographical research, musical analysis and performance practice. Special emphasis will be placed on key performance innovations and key composers and cross-pollination in popular musics.
The purpose is not to give a complete glossary of all extended performance techniques for the acoustic guitar, nor a technical performance guide, there have been many examples of this particularly in the last decade but to understand the impact of extended techniques through analysis of musical works. This is not to say that a large proportion of the extended techniques will not be included or discussed but as an ancillary to the investigation of the creation and propagation of the techniques in relation to musical composition and performance.
The acoustic guitar and its predecessors in the Baroque and Classical period have proven a popular instrument for performance, composition and general entertainment and for many centuries hence. The popularity has increased exponentially in popular culture since the introduction of the guitar in Blues Music of Deep South America in the beginning of the twentieth-century and furthered through the 1950’s Rock and Roll movement and is now often viewed as a synonym of Popular music. However, as will be demonstrated it is not merely an instrument for accompaniment or purely jovial entertainment: a wide range of Western art music composers and composer-guitarists have paved the way for a whole new range of performance techniques for the instrument.
The lineage of the acoustic guitar with its familiar approximate figure of eight shape, more often flatteringly seen as a metaphor of the female form is regularly cited to be from 15th Century Spanish culture in the form of Vihuela, but although not this is without contention as Grunfeld argues in The Art and Times of the Guitar, that there are clear depictions of very similarly shaped instruments dating back to the Hittite Era, approximately 1300BC. In addition, artwork with a close approximation of the guitar’s form was discovered in the burial tombs in the pyramids dating from the great fourth and fifth dynasties of Egypt, around 4000BC.
Since Egyptian and Hittite eras many other examples similar instruments following the same principle of sound production and propagation, the Cithara and Citharis (Lyre) which were evidently in existence in fourth-century BC. Although they share many common attributes to modern acoustic guitars, they’re not commonly regarded to what is now attributed as the prominent components of an acoustic guitar: a wooden tuneable fretted-neck instrument rested on the leg with several tuneable single or double courses of strings and a large sound box. This is the interpretation that will be used in relation to the ‘guitar’ referenced in these writings; the argument for the development of the guitar is not subject to recapitulation and analysis here.
What's Been Written About it Before?
Overall, the amount of literature specific to extended performance techniques on the acoustic guitar is limited, although it does occur as a consistent topic of investigation in the twentieth-century.
Extended techniques for the classical guitar have been investigated by several PhD theses, Robert Lunn’s 2010 thesis Extended Techniques for the Classical Guitar: A Guide for Composers offers an in-depth analysis of almost all techniques with specific examples in compositions, however as the title suggests the inclusion of steel-strung, electric and prepared instruments are omitted and similar to this work the intention is not to provide a technical study guide for performers, but discuss their application within musical contexts. How to Write for the Guitar – An Explanation for Non-Guitarist Composers by Rafael Andia (1983) offers an exposition of more practical performance issues to extended techniques, focussing on technical descriptions. However, none of the theses discuss the use of electronic augmentation such as effects processors or computer manipulation that are now relevant to modern extended guitar composers and performers.
A limited number of physical book publications have been written specifically on the subject, importantly these are more broad than the PhD aforementioned papers and include techniques for preparing the guitar with objects to further increase tone creation possibilities. Prepared Guitar Techniques by Elgart and Yates is a now an out of print and highly analytical work on the specific techniques and functional properties of different preparation methods for the guitar through two of the composer’s own works. Offers a very good list of some specific techniques.
Demonstrating the current relevancy of the topic, in April 2017 Mike Frengel’s The Unorthodox Guitar - A Guide to Alternative Performance Practice is released through Oxford University Press and although the full extent of topics cannot be known, the pre-publication description states that it will discuss, ‘alternative tunings, extended techniques, instrumental preparations, electronic augmentations, and issues related to performing and recording with a computer. For nylon and steel strung as well as electric guitars’. It appears then that this will be an invaluable resource for guitarists of all natures wishing to further explore the tonal landscape of the guitar; the issues relating to computer use will ensure that it is relevant for contemporary guitarist and setting it apart from existing works as mentioned above.
For conventions in notation Aloys Kontarsky’s essay ‘Notation for Piano’ appearing in the 1976 collection of essays Perspectives on Notation and Performance, discusses the often-overlooked difficulty of reading and the ‘correct’ interpretation of scores within a performance of specific passages; ‘Notation which seem quite feasible in the abstract often turns out, to be awkward, if not nonsensical, from a practical point of view.’. Although this work is focussed towards piano, there are similarities between the difficulties indicated here to the notation conventions on extended techniques discussed later, Kontarsky’s intention still remains.
What are Extended Techniques on the Guitar?
In a generalist manner, an extended technique is a way of creating sounds and timbres from an instrument that lay outside of the arbitrary accepted performance styles. On the guitar, arbitrary styles include playing fretted notes and plucking, strumming or picking with right-hand, whereas extended technique examples are hitting the guitar’s body in a variety of ways and places to create a percussive tone, bi-tones, artificial harmonics, multi-phonics, left-hand percussion, tambora and adding objects to the instrument, that will be further demonstrated.
A written discourse on such performances cannot be offered without at least a mention of John Cage’s ground-breaking Sonatas and Interludes for prepared piano, first recorded in 1951 (composition began in 1946), this collection of pieces was viewed by some as highly contentious and received in mixed regard by critics. John Cage’s use of extended techniques was not one of original artistic inspiration but that of functional ingenuity: faced with a lack of percussion instruments when working with a group of dancers in a Seattle school in 1940 Cage used the instrument for in place of percussion instruments. However, this was not the first example of extended technique, on other instruments earlier examples exist, such as the use of extended low–register technique when key slapping in Varese’s Density 21.5 published in 1936. Also, custom micro-tonal guitar were created by composer-performers in the 1940’s.
Early Innovations in Extended Techniques
The physical construction of the acoustic guitar does indeed lend itself to an array of tonal exploration; the relatively large four octave range of the instrument from E2 to E5 and E6 on many instruments coupled with the resonant wooden body acting as an amplifier all allow the potential experimenter many different timbres of dynamics and tone-creation locations.
Before the advent of the earliest extended techniques, performers and composers on the classical guitar and it’s precursors were still able to explore timbral nuances: considering both contact points in the sound propagation comes from the performer’s hands a wide-range of approaches to exciting the strings are possible, from the warm timbre produced by plucking close or over the fretboard converse to picking at the bridge to create a bright but thin tone, that is often found in many classical and Flamenco compositions. Furthermore, the length of the nail (if used at all, much less so in contemporary steel-strung acoustic guitar performance), shaping of the nail, angle of finger attack and off-axis plucking all have an impact on the tone produced. With such a variety of variables every guitarist has a slightly different tonal signature, whether from intentional training or natural development and when coupled with a performer’s particular interpretive approach or style, guitarists are sought for their individual qualities. For example, classical guitar contemporaries Julian Bream and John Williams have subtle but very real differences, during their hey-day in the 1960-90’s both guitarists had their supporters and critics. Williams has a more traditional approach to right-hand position and has much power and clarity in his playing, whereas Bream often has a wider variation of vibrato alongside a more un-orthodox right hand position that enables Bream to achieve further tonal colour, this slight drag across the string when plucking is demonstrated in John Mills’ video discussing tonal colour of the classical guitar. Many contemporary pieces utilise this nuance and Don Ross’ ‘First Ride’ serves as an ideal illustration to the variety of timbres available through the augmentation of angle of the thumb, resulting in modification of the melody timbre through the introduction of a purposeful nail scrape in one theme.
Further exploration of the timbres available on the acoustic guitar led to a natural progression of the development of extended techniques. To understand when this occurred, one must look to the recorded history of guitar performances through written notation conventions. The earliest tablature publication for the Vihuela in 1535 by the great Spanish contrapuntal composer Luis Milan, whose Libro De Musica de Vihuela de Mano Intitulando acted not just as a set of musical pieces but as a beginner’s guide to guitar performance with suggested fingerings, explanation of technique etc. and has no reference to any simple extended techniques, and nor do the two other 16th century instructional books by Luis De Narvaez and Alonso Mudarra provide any examples of what would now be defined as extended techniques.
It is worthwhile to note at this point, the looked-down upon view which tablature is regarded in Western-Art music in the last two centuries, as tablature proceeded written notation for the guitar by nearly 250 years, this popularity of tablature is no doubt of fundamental importance to the proliferation of the instrument and its music in societies, in addition or the increasing availability and popularity of the instrument in the twentieth-century.
So, if these early examples held no examples of extended performance techniques, one must look forward to early examples of notated extended performance technique for other strung instruments for clues for development, such as that appears in Gustav Mahler’s Symphony No.7 in what has become known as Bartok Pizzicato, due to the popular misconception of the attribution of the technique to Hungarian composer Bela Bartok, however according to Normal Del Mar’s The Anatomy of the Orchestra, it was in fact Gustav Mahler to first utilise this technique in 1902. The technique of applying pizzicato with enough right-hand plucking force so the string slaps back on the fretboard in a percussive manner whilst also sounding the fretted note, there operates on a similar principle to that of slap-bass that developed in the two decades following.
Another technique that developed early in the course of extended techniques is one that is also the most simple and naturally performed: Tambora, a percussive effect produced by striking the strings near the bridge with the thumb, to create a pitched percussive effect, which has its roots in Flamenco performance traditions and is likely to have been used in non-notated Spanish Folk music traditions before that of any other performance technique. Furthermore, in the previous century, it has become more popular in Classical guitar pieces. This is an excellent example of a crossover extended technique that has permeated into popular music; Led Zeppelin’s ‘Your Time is Gonna Come’ features exactly this, played by Page to introduce the second verse at 2:35-2:40 with anticipatory energy . The fundamental of this technique, and that of Bartok Pizzicato, exhibit many parallels to ‘Slap’ Bass, often cited as developed by American Jazz double bassist William Manuel Johnson, dubbed ‘the father of slap bass’  in the 1910/20’s. Further developments of string-slap based techniques and textural layering is owed to Michael Hedges’ landmark debut album Aerial Boundaries (1984) where within the title track a plethora of slapped harmonics and tambora. More recently, Newton Falkner is widely known for his similar slap technique and percussive performances in the 2000’s.
Therefore, the creation of extended techniques can be seen to be a multi-faceted development; examples born from necessity addition to musical experimentation, and so, the proliferation of extended techniques on the acoustic guitar has a symbiotic relationship to the development of contemporary genres and stylistic traits of the post 1900 musical landscape.
Jimmy Page famously used a bow to good effect in his work with Led Zeppelin, thus enabling him to completely transform the dynamic envelope of the instrument from sharp transient attack of the fingers or plectrum to a far more sustained dynacism with a far less abrupt attack. This technique used in this context certainly can be seen to be original but arguably it is now seen as more of a novelty token and was not, nor is now used prolifically. However, this Arco style on the guitar can be deduced back to the Spanish Vihuela of the 16th Century where specific instruments were produced for particular playing styles: Vihuela Arco (Bowed), Vihuela Penalo (Quill Plectrum) & Vihuela Mano (Fingers). So, it is evident that the creation of a variety of timbres from a single instrument did not escape the Vihuela composers five-hundred years ago, such as Robert De Visee, Luis Milan et al.
The modern equivalent of bowed timbres for typically non-bowed instruments can be seen in the e-bow, a hand-held electronic device to induce the gradual attack and indefinite sustain of a bowed string, through inductive string driving. Release in 1976, it has been popular for electric guitarists to manipulate the dynamic envelope of a string, mimicking electronic instruments, as will be seen later with Muse guitarists Matt Bellamy. It is not only guitarists that have benefitted from this device, experimental contemporary composers such as Ed Bennet have used it to great effect on the piano.
Later in the twentieth-century, Japanese composer Toru Takemitsu’s admiration of the classical guitar and its harmonic qualities and expressiveness of timbre led to Takemistu’s two seminal guitar suites All in Twilight (1987) composed specifically for Julian Bream and In the Woods (1995), both feature modest but thoughtful use of artificial harmonics, a technique used to extend the number of harmonics available on the instrument by lightly placing the right index finger twelve frets above the position of the left-hand fretted note and plucking with the right thumb, resulting in an octave harmonic through reduction of the nodal length of the vibration on the string by half (therefore a doubling in pitch). Artificial harmonics are employed in large aggregation by world-renowned Australian virtuoso Tommy Emmanuel whose use on the steel-strung acoustic medium not only shows cross-discipline application of the technique but also further relevance in popular music. Emmanuel’s interpretation of ‘Somewhere Over the Rainbow’, as many of his compositions, display a more fluid approach to the application of the technique with swept runs and arepeggiated chord voicings; contrasting to the sparse use in Takemitsu’s pieces and deliver the technique further into popular music and wider audience appreciation.
Other compositions veered further on the side of Avant-Garde in terms of form, melodic and harmonic intentions. For example, Giacinto Scelsi’s Ko-tha (1967) is a highly unusual work that instructs the performer to lay the guitar on the lap or table and using a thumb to strike the open strings in a manner that seems agreeable to the performer at the time recital. A few recorded examples exist that demonstrate the ambiguity of the composition. It would be very unusual for this technique to be seen in relation to Pop or even popular music examples due to its atonal and freeform nature, there is no hook that is so important in Pop music.
The use of percussive elements in the right-hand finger and thumb strumming technique of Spanish Folk and Flamenco music is highly prevalent with the technique Rasgueaudo, where rapid finger strokes in ‘hundreds of different patterns’ are used to create forceful percussive effects, where so much force can be used to approximate Bartok pizzicato.
Notation and Scoring Conventions for Extended Techniques on Acoustic Guitar
As seen in the previous chapter, the application and delivery of meaning in performance can be seen from different interpretative ideologies, the same methodology can therefore apply to notation conventions of extended musical techniques. In this aspect, the guitar developed relatively late; earlier composers utilising extended techniques overcame the boundaries of the delineation of ubiquitous rhythm, pitch and dynamic markings within pre-modernist notation much sooner. The popularity of the guitar as a social instrument for accompaniment, and lower-classes during the seventeenth and eighteenth centuries may have been a major factor in the late development of notation for the instrument: it was not until Fernando Farandiere wrote and published Arte de Tocar de Guitarra Espanola por Musica in 1799, that the instrument had a written guide to playing notation , whereas previously tablature had only been available.
The earliest extended technique pioneers had to devise their own idioms of notating their new extended techniques in manuscripts, where new symbols could be created or specific performance instructions given in the score, much similar to graphic and written conventions in the Modernist movement. It could certainly be argued that in some ways, the creation of new notation symbols is more difficult owing to the prevalence of computer programs with a set system of notation marks that are widely in used today, this would require new updates from the developer for inclusions of new symbols. This can be seen especially with the rise of the popularity of percussion techniques as a means of self-accompaniment through the proliferation of the technique through key figures such as Andy McKee, Tommy Emmanuel, Don Ross, Newton Faulkner et al. in popular guitar magazines’ notation convention. Herein arises another difficulty, the instruction of extended techniques in the ever popular tablature form, In 2015 Guitar World’s article ‘Beat It: A Guide to the Inspired Techniques of Percussive Acoustic Guitar Playing: Mike Errico’, Erico uses existing star symbols with further written instruction, thus
As it can be seen, the tablature could get messy and confused quite quickly, especially if trying to sight-read.
So then, it is evident from examples of 20th century notation that there is no single standard convention for notating extended techniques for the instrument. Alberto Ginastera’s 1975 Sonata for Guitar uses the example in fig.4 for denotation of the ‘highest indeterminate possible’ strummed barre chord
Whereas, Georgio Maletti’s seminal transcription of Tommy Emmanuel’s Classical Gas, notates differently thus in fig.5. What is evident is Maletti’s grounding in traditional rhythmic conventions with the grouping of notes. Therefore, it could be argued that Ginastera’s notation leaves more room for interpretation from the performer as no rhythmic direction is given, although certainly a quintet group of demisemiquavers would be a challenge to play strictly in any case, especially considering the indicated BPM of 192.
Many of the examples seen in the previous chapter illustrate the popularity of the of the nylon strung Spanish guitar as the medium for tonal exploration, but the availability of steel strings and structural reinforcement of the guitar in the early 1900’s by C.F Martin and development of the electric guitar and related electronic devices, giving a new pallet of timbres to guitar composers and performers.
Fred Firth and Keith Rowe, both 1960’s pioneers in ‘prepared’ electric guitar were key innovators in the then new field of preparing the electric guitar: the adornment of object onto the guitar including paper clips on the strings at resonant points, bull-dog clips, placing nails on the fretboard so that controlled buzzes could be created. These experimental developments led to Rowe’s album Guitar Solos (1974) followed by two further themed albums of the same name. Current day equivalents have been developed further into a barely recognisable instrument, laid on a table surrounded by prepared electronic devices, somewhat unsurprising considering the rise of the avant-garde and psychedelic rock of the era, examples in the music including Syd Barret era Pink Floyd’s interstellar Overdrive, with distorted shaken and often atonal guitar parts.
Furthermore, the introduction of microphones and Piezo pick-ups and pre-amps in acoustic guitars, more commonly now known as electro-acoustic guitars, in the 1950’s further paved the way for tonal-exploration that now can be heard utilised to great extent in performers such as Jon Gomm, Tommy Emmanuel, Newton Faulkner et al. The addition of microphones inside acoustic instruments allow for a greater resolution of normally barely audible artefacts, such as the left hand percussive attack in the rhythmic section produced in much of Michael Hedges’ Aerial Boundaries album. With current recording technology, the finer nuances of tone production can be honed and extenuated as necessary, further leading to the proliferation of the unaccompanied solo acoustic guitar performer.
The application of altered tunings has increased exponentially throughout the second half of the 20th Century, with music chart-featured songwriters such as Nick Drake using the increasing pitch range and tonal possibilities to good effect in tracks, furthermore, this possibility has been assisted due to developments and availability of different gauge strings, packs of strings are now available for specific tunings in mind, another example of music and technology working symbiotically. Canadian contemporary fingerstyle guitarist Antoine Defour discusses his approach to effective ordering of set-lists when using an array of tunings (he travels with just one guitar) “I try to organise my set list with the tunings that are closest together, and I try to group similar tunes. I start strong with something simpler and end with the harder ones.” (Defour, 2015), so here it can be seen that travelling with a single instrument is as valid for any performer, although it is not without risks and nor are any of the more forceful extended techniques without risk of damaging an instrument over time.
Tommy Emmanuel has used sandpaper to remove the cellulose finish from a portion of the guitar’s soundboard and uses a brush drum-stick to create jazz-themed brushed snare timbres whilst his left hand tapping a bass line. Furthermore, Emmanuel’s use of percussive sounds is evident in his intimate concerts and Ted-Talk, where he discussed in length about the different tone and percussion approaches in his ‘one man band’ perspective to performance.
Extended Techniques in Popular Music
The very definition of popular music is a contentious one, with differentiations from popular music, that is, one that by definition is popular with a large audience in Western music and that of Pop music, coming from the cultural music explosion of the 1950’s. Popular music is this investigation is one of popularity within the Western audience.
The use of pick slides, that is running the pick down the length of the string, usually the ‘low E’ emerged from the Rock/Punk movement during the 1960’s, and further popularised in an array of popular music from rockers Bon Jovi to Gerry Rafferty’s Pop hit Baker Street (1978), where during the chorus it is applied to offer tonal thickness and the impart much of the energy from the genre in which the technique was conceived.
Another extended technique to have come from popular electric guitar repertoire is 2 hand tapping, where hammer-on’s on both hands are used, usually for virtuosic speed and other wise unplayable distances between rapid notes, one of the most well-known examples in Van Halen’s Eruption (1978). This has become more popular with solo acoustic guitar performers, such as Jon Gomm’s 2013 Passionflower, where the technique is used to imply a bass-line over constructed Lydian-modal melody that would otherwise be unplayable and further evidence of the cross-pollination between niche and popular styles.
Jimi Hendrix’s approach to playing the guitar was unarguably unique, commonly ferociously using the tremolo arm of his Fender Stratocaster and more unusually using his teeth to pick the strings, and although this may not have always produced the most musically accurate note reproduction, the timbre and visual imagery produced and disseminated meaning in a highly original way, one that captured the audience’s imagination and thus it is in a similar manner that acoustic extended techniques can create abstract expressions and can be seen as a valid approach to composition and performance as any.
The introduction of the tremolo system could be argued to be the first evidence of the modification of a guitar for extended techniques. The first mechanical commercially available tremolo system, Vibrola patented in 1936 and designed by Doc Kauffman was the pre-cursor of all following tremolo systems such as the Bigsby popular in Jazz and Fender’s own floating system. The new sonic possibilities were sought by budding guitarists and many household names in guitar utilised the system to great effect, most notably Hank Marvin of the Shadows and Dick Dale; the sound of the tremolo would become synonymous with the Surf music rock sub-genre of the early 1960’s demonstrating the symbiosis between technological development and musical development. More recently the development of the locking nut and Floyd-Rose tremolo systems have allowed for a new ferocity in the application of tremolo in performance and development of specific techniques that are now defining traits of Rock and Heavy Metal styles, such as that of the ‘dive-bomb’, where examples litter the genre such as Joe Satriani’s Surfing with the Alien.
The acoustic guitar’s fragility compared to that of the electric would seem to exempt it from such a system, however Bryan Adams played a modified Martin acoustic guitar with a Bigsby tremolo system during his 1999 MTV Unplugged performance, the guitar can be seen on the cover of the live album by the same name. In 2010 Predice Hendricks received a US patent for his PHAT (Predice Hendricks Acoustic Tremolo) system, which uses a similar principle to the electric guitar counterpart however, this must have had limited popularity as no examples exist in popular music, and since 2010 the PHAT website has become inactive.
Here it can be seen that new extended techniques can be a function of technological advancement, just as much as they can be the driver of new advancements. To this end then, the development of modified and custom instruments seemed a logical next step, which is what will be discussed in the following chapter.
Modifications and Custom Instruments
Modification of the guitar is pivotal to the fundamental principles of the prepared guitar, one of the earliest innovators in prepared/extended guitar luthiery is American guitarist/composer and theorist Harry Partch, who upon requiring a guitar to play his own 43-note octave musical tuning system, re-fretted and modified two guitars, somewhat unimaginatively called Adapted Guitar 1 in 1934 and Adapted Guitar 2 in 1945, although the guitars were designed to be played laid on the lap rather than the typical playing position. Following on from Partch’s functional guitar development Norwegian Composer Bjørn Fongaard created a similar instrument in the 1960’s with a quarter-tone fretted system and often wrongly attributed as the first prepared guitar luthier. Since, there have been several luthiers for specific prepared guitars such as Yuri Landman, Glenn Branca and Bradford Reed.
At the end of the twentieth-century with the availability of low-cost electronics and resurgence in popularity of electronic music led to further interest and developments to the guitar as a multi-tonal instrument with pioneering instruments such as Muse guitarist Matt Bellamy’s 2008 Manson-built electric guitar with a MIDI (Musical Instrument Digital Interface) controller built-in to the body to allow the player to control any MIDI compatible synthesiser, stage lighting or sound generator and in theory due to many large firework displays being controlled by the MIDI protocol, large-scale pyrotechnic display control could also be achieved! Additionally, installed in the Manson MB-1 is a Fernandes Sustainer, a device that operates on the same principle as the aforementioned e-bow, that forces sustained string vibration through magnetic induction built into the body of the guitar, allowing for more electronic timbres.  The development of this guitar can be viewed as the current conclusion of Rowe and Frith’s experimentation in the 1960’s with prepared electric guitars.
In 2013 pioneering American acoustic guitarist released the Passionflower album, with the title track being played on a modified Lowden acoustic guitar, where the E and B strings’ tuning mechanism were replaced by Bill Keith locking banjo tuners, enabling Gomm to ‘conjour ethereal sounds and impossible melodies from the guitar’, this has certainly been demonstrated by the very musical application of tuning up and down within the main melodic device of Passionflower. Such an innovation that Lowden now produce a Jon Gomm signature model with these same modifications and Rare Earth pickup and microphone system.
What is the actual importance of extended techniques, beyond the exploration of further tonal avenues, that in all fairness could now and since the 1970’s be produced relative reliability and accuracy through samplers in live performance? Although performance has changed dramatically through the course of live music, there still must be value in the perceived virtuosity and experimentalism by an audience. Ignoring the dated opinions of Thomas Fielden’s book Music and Character (1931), who goes are far to define popular music as no more than a ‘frivolous endeavour’ and certainly not for the intellectual listener; contemporary and popular music is an environment in which a variety of extended techniques discussed in this essay have been able to flourish and develop into a part of the established technique repertoire for acoustic guitar in popular music.
One must also consider the semiotic significance of extended performance techniques: the original meaning giver may be the composer. The composer’s implied meaning of each application of a technique cannot truly be speculated, only the composer can know this, however informed judgements can be made through examining the context in which it occurs and therefore a performer playing another composer’s work may not realise the music as the composer intended, unintentional diluting or transforming from the written notation. A different perspective on these facts perhaps, is to see the value in the interpretation of a performance technique from the performer and often specific performer, it is true after all that many cover versions have become more popular than the original.
The development of extended techniques, particularly unusual ones has often thought to be at a distance from popular and Pop music and a part of the avant-garde and used only as specific effects, however it has been shown here that these have permeated popular music culture in a number of guises and in some cases, been important in the development of new movements that led to the formation of new genres: something that is far from a novelty or whimsical appreciation. It is clear that the progressive experimental ideas of prepared guitar is still yet to be shown in popular music entirely, but audiences, scholars, luthiers, composers and performers for these activities all continue to show the importance and intrigue of extended techniques.
We have seen that the development of extended techniques and technologies develop concurrently and they continue to influence one another and offer momentum to progress. Similarly, the popularity of unaccompanied solo-acoustic guitarists has led to further development of the technicalities and application of the techniques, as these composer/performers strive to inflate the sound spectrum that is offered to the audience.
That said, it is true that no popular genres have, or currently are based solely, or largely upon extended techniques. A genre based on purely demonstration of performance techniques alone is, and never likely will be at the top of the charts and popular in the mainstream. The continued examination of extended techniques through written publications, whether PhD and MA theses, printed books or entries in popular guitar magazines show the relevance of the topic in popular musical and scholarly circles in addition to the forthcoming publications in 2017.
 Evans, David. The Guitar in the Blues Music of the Deep South (1995) p03
 Tyler, James. The Early Guitar (1980) p15
 Grunfeld, Frederik. The Art and Times of the Guitar (1974) p26
 Lunn, Robert. Extended Techniques for the Classical Guitar: A Guide for Composers (2010) and Andia, Rafael. How to Write for the Guitar – An Explanation for Non-Guitarist Composers by Rafael (1983)
 Lunn, Robert. Extended Techniques for the Classical Guitar: A Guide for Composers (2010)
 Andia, Rafael. How to Write for the Guitar – An Explanation for Non-Guitarist Composers by Rafael (1983)
 Frengel, Mike. The Unorthodox Guitar (2017) Rear Cover
 Kontarsky, Aloys. Notation for Piano (1963) p01
 Grove Music Online. Extended Techniques (N.D)
 Larry, David. John Cage: Innovator (1998)
 Heiss. James. The Flute: New Sounds (1976) p01
 Partch, Harry. Instruments. (2016)
 Mills, John. John Mills discusses tone colour on the classical guitar (2008)
 Ross, Don. First Ride (1999)
 Milan, Luis. Libro De Musica de Vihuela de Mano Intitulando (1535)
 Online archives available at <http://bdh-rd.bne.es/viewer.vm?pid=d-201461>
 Grunfeld, Frederik. The Art and Times of the Guitar (1974) p140
 Del Mar, Norman. The Anatomy of the Orchestra (1981) p98
 Led Zeppelin. Your Time is Gonna Come (1969)
 Singleton, Joan. Keep it Real: The Life Story of James “Jimmy” Palao “The King of Jazz” (2011) p60
 Hedges, Michael. Aerial Boundaries (1984)
 Grunfeld, Frederik. The Art and Times of the Guitar (1972)
 Takemitsu, Toru. All in Twilight (1987)
 Takemitsu, Toru. In the Woods (1995)
 Emmanuel, Tommy. Somewhere Over the Rainbow (2005)
 Scelsi, Giacinto. Ko-Tha (1967)
 Bonavita, Sal. Rasgueaudo Mastery Part 1 (2016)
 Grunfeld, F; The Art and Times of the Guitar (1974) p140
 Grunfeld, F; The Art and Times of the Guitar (1974) p82
 Guitar World. Beat It: A Guide to the Inspired Techniques of Percussive Acoustic Guitar Playing: Mike Errico (2015)
 Ginastera, Alberto. Sonata for Guitar (1974)
 Emmanuel, Tommy. Classical Gas (1973)
 Defour, Antoine. An Interview with Antoine Defour (2015)
 Emmanuel, Tommy (2010) Ted Talk: My Life as a One Man Band. 3:15
 Gomm, Jon. Passionflower (2013)
 Kohman, Peter. Epi-Phonic Echoes, Part Five: Masterbuilt Oddities (2011) p66-67
 Bryan Adams Acoustic Tremolo System
 Hendricks, Predice. The PHAT System (2012)
 Partch, Harry. Instruments (1962)
 Sneider, John. The Prepared Guitar (1985) p56-70
 Varian, Ethan. Manson MB-1 Guitar is Muse Guitarist Matt Bellamy’s Secret Weapon (2011)
 Gomm, Jon. Guitars (N.D)
 Fielden, Thomas. Music and Character (1931) p13
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