Writing Microtones for Guitar 197 Agustín Castilla-Ávila Writing Microtones for Guitar In this artcle, I would like to present my ideas in a personal and biographical way. I will describe the situaton of microtonal guitars I found as I decided to create a 36-division system and to compose for it. I will write about the deci- sions I made as a guitarist and a composer. First, I would like to explain a few ways to obtain microtones on an ordinary guitar. They are: 1. by manipulatng the tuning pegs using any microtonal interval; 2. by bending the string (like in blues guitar music); 3. by plucking between the lef hand and upper nut (so that the proport- ons of the fret divisions are inverted) and 4. by using special scordatura changing the strings. 1 Practical problems with diferent microtonal guitars There is a wide range of microtonal guitars using either fxed frets, movable frets, or fretless systems. They also provide a wide range of microtonal scales like equal divisions, just intonaton, or Arabic or Middle Eastern scales (or any microtonal scale from any culture). I fnd all these instruments, especially those built in the twenteth century, to be very fascinatng. But if we take a look at some microtonal guitars (i.e. John Catler’s), most guitarists might fnd a pract- cal 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 an ordinary one) and learn a specifc technique for it. It means a great amount of money and tme invested for a very small repertoire writen for those in- struments. In my own case, stll as a guitar student at the Conservatorio de Sevilla back in the ninetes, 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 fnd my own way to produce the microtones efectvely without changing my instrument or my technique: from string to string.