http://www.castilla-avila.comAgustin Castilla-Avila

Presentation of the lecture "Microtonality on the Guitar"

My name is Agustín Castilla-Ávila. I am a composer, guitarist and vice-president of the Austrian Microtonal Society. I would like to apply to present a proposal for 60 minutes lecture about microtonality on the guitar.


I have developed a sixth-of-a-tone system for classical guitar (on an ordinary guitar). I use six equal strings tuned at sixths of a tone. That allows any guitarist to play microtonal music without acquiring a special guitar of developing a special technique for it. The lecture is not only interesting for guitarists but also for composers who can get many new ideas about the possibilities of the guitar. These ideas will be included in "The contemporary Guitar" by John Schneider or in Franck Jedrzejewski´s "Dictionnaire  des musiques microtonales". My microtonal pieces have been recorded by Giacomo Fiore for Spectropol Records or by Joseph Mirandilla for Zay Records.


In the lecture, I present several microtonal guitars and defend why I chose my sixth-of-a-tone system; I show what it can be done with this guitar and its details (such as notation). I normally present all the information connected to my personal decisions as a composer.


I presented this lecture at universities such Reina Sofia in Madrid, Mozarteum in Salzburg, Yong Siew To Conservatory in Singapur, Boston University, etc. I attach a proposal, my cv and an audio example.


Here is an example of my work:



For more information, you could visit:


 "The future of microtonal guitar" Prof. Julia Werntz, artistic advisor of the Boston Microtonal Society.




Agustín Castilla-Ávila presents his own microtonal system on the guitar:


1.    Fascination about the String and microtones on the guitar.

Historic uses of the string and different possibilities to use microtones on the guitar.


2.    Practical problems with different microtonal guitars.

Different microtonal guitars and their practical problems for guitarists. Gallery of microtonal guitars.


3.    The guitar in sixths of a tone.

Advantages and disadvantages of tuning in sixths of a tone. Personal decisions of the composer. Examples from solo to sextet.


4.    Notation: Transcription or tablature?

Advantages and disadvantages of the different notation ways.


5.    Prepared guitars and other ways to get microtones on the guitar.

Microtones on the prepared guitar. Discussion about “the lost intimacy of the guitar”.


6.    Questions





Born in Jerez, Spain. He studied guitar at Conservatorio Superior de Sevilla. Further studies at London College of Music with guitarist C. Bonell, at Guildhall School of Music with guitarist R. Brightmore and the composer M. King, at Mozarteum with I. Siewers and at Arizona State University with F. Koonce. Composition studies at Mozarteum under A. Hölszky and R. Febel and at Luxemburg Consevatoire with A. Müllenbach.

Master classes from D. Russell, M. Barrueco, R. Dyens, etc.; and from S. Sciarrino, D. Schnebel, C. Halffter, etc. He taught at Ceuta Conservatory, Lucena Conservatory (Spain) and at Arizona State University.

He had concerts in Europe, Asia and USA. His music has been conducted by D. Russell-Davies, T. Ceccherini, J. Kalitzke, H. Lintu, A. Soriano, H. Schellenberger, etc.

He has written solo, chamber music, orchestral, theater plays, choreographies and four chamber operas. He publishes for Doblinger Verlag.

He has been awarded with the Music Prize 2013 from the Region of Salzburg.


-“A very high degree of originality, he is always in search for new horizons”. Alexander Müllenbach.



Castilla-Ávila´s Lecture "Microtonality on the Guitar”


MicroFest Amsterdam 2015, Holland


Royal Musical Association Annual Conference. University of Birmingham,  UK

Simposium “Mikrotöne: Small is beautiful”, Universität Mozarteum. Salzburg, Austria


Conservatorio Superior de Música de Vigo,  Spain


5th Lake Konstanz Guitar Research Meeting 2015. Hemmenhofen,  Germany

Universidad de Valladolid , Spain

Centro Superior de Investigación y Promoción de la Música de la Universidad Autónoma de Madrid, Spain

Conservatori Superior de Música "Joaquín Rodrigo", Valencia,  Spain

Istanbul Technical University, Turkey

Conservatorio Superior de Música Óscar Esplá. Alicante, Spain
Conservatorio Superior de Música Música de Málaga, Spain
Aspen Composer´s Conference. Aspen, Colorado, USA
Congresso de Organologia 2014. Museu Nogueira da Silva, Braga, Portugal
Symposium to launch the International Guitar Research Centre at the University of Surrey, UK
Gotlands Tonsättarskola. Visby, Sweden
Royal Danish Academy of Music, Copenhagen, Denmark 
"Beyond the semitone" Symposium. University of Aberdeen, Scotland
NACUSA 2013 National Conference Meeting, Louisiana Tech University, Ruston, Louisiana, USA
Donau Universität, Krems, Austria
KIBLA Festival. Maribor, Slovenia
Anton Bruckner Universität. Linz, Austria
Composer`s Talk. Passau Saiten Festival, Passau, Germany
Conservatorio Profesional de Córdoba, Spain
Carl von Ossietzky Universität Oldenburg, Germany
Atheneaum Conservatory, Athen, Greece
Sichuan Conservatory, Chengdu, China.
Boston University, Boston, USA
Composer's portrait. Mondseer Kultur Verein, Mondsee, Austria
"Music of our Time", Composer's Portrait.  Sommerakademie Mozarteum Salzburg, Austria
Kongress Mikrotonalität Stuttgart. Staatliche Hochschule für Musik und Darstellende Kunst Stuttgart, Germany
Tage der mikrotonalen Musik. Universität Mozarteum Salzburg, Austria
Conservatorio Superior de Música “Manuel Castillo”, Sevilla, Spain
Conservatorio Teresa Berganza, Madrid, Spain
Yong Siew Toh Conservatory of Music, Singapur
Filipino Guitar Foundation, Cebu, Philippines
University of Santo Tomás, Manila, Philippines
Santa Isabel College, Manila, Philippines
Guildhall School of Music and Drama, London, UK
Saint Louis University, Madrid Campus, Madrid, Spain
Maison du Mexique, Paris, France
Escuela Superior de Música Reina Sofia, Madrid, Spain
“Faszination der Saite.” Lecture and concert. Schloss Puchberg, Wels, Austria
Saint Petersburg Conservatory, Saint Petersburg, Russia
Woche der Mikrotonalen Musik. Mozarteum University, Salzburg, Austria
Internationales Symposium West-östlicher Einklang Festival. Saint Virgil, Salzburg, Austria
Österreichische Gesellschaft für Neue Musik, Vienna, Austria





"Microtonality on the guitar: Castilla-Avila´s 36 divisions of the scale"



In this article, I would like to present my ideas in a personal and biographical way. I will describe the situation about microtonal guitars I found as I decided to write for microtonal guitar and talk about the decisions I made as a guitarist and composer.


How to obtain microtones on an ordinary guitar


First of all, I would like to explain a few ways how to obtained microtones on an ordinary guitar. Those are:

1.     By manipulating the tuning pegs using any microtonal intervals

2.     By bending the string (like in blues guitar music)

3.     By plucking between left hand and upper nut (so that the proportions of the fret divisions are inverted) and

4.     By using special scordatura changing the strings.


Practical problems with different microtonal guitars.


There is a wide range of microtonal guitars using either fix frets, movable frets of fretless systems. They also provide a wide range of microtonal scales like equal divisions, just intonation, Arabic or Middle East scales (or any microtonal scale from any culture). I find all these instruments build especially in the 20th century very fascinating. But if we take a look at some microtonal guitars (I.e. John Catler´s), most guitarists might find a practical problem with them: they have to deal more or less with a new instrument. They need to acquire a new one (which in many cases is more expensive than the ordinary ones) and learn a new specific technique for it. It means a big amount of money and time for a very small repertoire written for those instruments. In my own case, still as a guitar student at the Conservatorio de Sevilla back in the nineties, I was not planning to specialize in microtonal guitar repertoire. My aim was to be able to include some microtonal music in my programs. As we see in those guitars, the microtones are produced from fret to fret. I had to find my own way to produce the microtones effectively without changing my instrument or my technique: from string to string.


The guitar in sixths of a tone.


I tried out several microtone intervals in different registers (I.e. quarter tones, eighth tones or thirds of a tone on different equal strings) and I must say that the ones I prefer the most are the sixths of a tone (especially using six G strings). By doing so, all six open strings remain within a tone (from sixth to first: F sharp minus a third, F sharp minus a sixth, F sharp, G minus a third, G minus a sixth and G). By most of the microtonal guitars, playing open strings is exactly the same as by ordinary guitars. Having the microtones between the strings gives a special resonance, which I personally like very much. This system using six equal strings is very open to any tuning. In fact, this year I am working on a new microtonal piece ("Der Nacht der Wellen" ) using 12ths of a tone.

In the solo pieces (played by Joseph Mirandilla in the examples) “Tres Momentos Microtonales” (, and “Sakura” ( I use six G strings tuned at sixths of a tone from string to string. This allows a kind of bass and melody in a very effective way. In the same way but with six bass E strings is written strings “Il Velo di Iside” (played by Giacomo Fiore: This work explores both the microtones in a low register and high-registered microtones produced by plucking between left hand and upper nut.

After composing within this register (only a little more than an octave and a fifth, depending on the guitar, since from the sixth string to the first one there is only five sixths of a tone), I chose to enlarge the register was to use two guitars (one with all E strings and the other all G ones, both tuned at sixths of a tone). The result is not just around two octaves and a half (depending on the guitar) but also a colour contrast; a set of six high E strings sound much more sharp than one of six G strings. “Das klingt sehr mikrotonalisch” ( is an example (played by Cecilio Perera and Emerson Salazar) of my compositions for two microtonal guitars.

In order to have both the ordinary register of the guitar and all the microtones in between and its authentic resonance, my choice was to write for six microtonal guitars (each consisting of six times each strings with the same tuning): “Rubaiyats” (

Most of the guitarists who played my microtonal pieces had no experience with this kind of music. Since the frets are not manipulated, it has been very easy for all of them to adapt their playing to this system. This is one of the biggest advantages of this system. I have not yet written for any of those microtonal guitars with a special fret system because of two reasons. In one side, microtonal guitar music is just a small part of my work. And on the other, I believe there is still much to develop with scordatura microtonality. What I find most fascinating about this microtonal scordatura is the resonance of the instrument. I personally use this guitar as a bridge between contemporary music and music from different cultures involving microtones (Arabic, Japanese, etc.).

Sometimes I composed using some variations to this system in different pieces (combining it with different ways to obtain microtones). In “Tres Tristes Tríos”, I distribute the sixths of a tone among three guitars without changing the strings at all:



Example from “Tres Tristes Tríos”


Notation: Transcription or tablature?


One of the big problems of writing using this microtonal guitar I had to challenge was the notation. Since most of guitarists are familiar with different kinds of tablature, I created one indicating the string and the fret (the head of the note to indicate ordinary, harmonic, percussive, etc.). I used this system in compositions such as “Tres Momentos Microtonales”:


Example from “Tres Momentos Microtonales”


Using transcription is a possibility for the guitarist to learn the piece in a very quick time. Depending on the textures (thick textures are much better for the performer written transcribed). I used it in in compositions such as “Sakura”:



Example from “Sakura”


Concerning the notation, I mainly focused on practical aspects helping the performer learning the composition. Only when asked, I provide an ossia line with the sounding notation (especially when I use this system in chamber pieces). A notation like this is very confusing for the performer, as they have to recognize the notes in completely new positions.


Prepared guitars and other ways to get microtones on the guitar.


As a composer, I also like very much the guitar microtones produced by plucking between left hand and upper nut. By doing so, the resonance body of the instrument is avoided. I am not at all against the evolution of the instrument (especially concerning the volume) since the Torres guitars around 1850. But when I listen to the very powerful (and beautiful) guitars today, I have the feeling that we have lost the intimate character of it. This is the aesthetical reason why I keep writing intimate guitar pieces (“without” resonance body). I also use preparations sometimes (preferably with guitaristic elements such as fix capotasto on the 10th fret or a cloth under the strings) so that the sounding part of the string will be connected to the upper nut. One last example of my microtonal compositions during my presentation was “Caged Music 3” played by Athenaeum Guitar Trio:



2011:     Magisterstudium Komposition an der Universität Mozarteum Salzburg

2008:     Bachelorstudium Komposition an der Universität Mozarteum Salzburg

2007:     Diplôme de la Division Supérieure am Conservatoire de Musique Ville de Luxemburg

2002:     Postgraduate Studium in Gitarre am Mozarteum Universität Salzburg

2001:     Postgraduate Diploma in Music Performance an der Guildhall School of Music and Drama, UK

2001:     Master of Music an der Guildhall School of Music and Drama, UK

2000:     Postgraduate Diploma in Music Performance an der Guildhall School of Music and Drama, UK

2000:     Master of Music (Performance) am London College of Music and Media, UK

1999:     Titulo de Profesor Superior (especialidad Guitarra) am Conservatorio Superior de Música de Sevilla, Spanien

1996:     Titulo de Profesor (especialidad Guitarra) am Conservatorio Superior de Música de Sevilla, Spanien

1992:     Highschool am William Tennent HS, Warminster, Pennsylvania, USA