He was born in Jerez de la Frontera, Spain, where he began his musical studies at its conservatoire. Later he entered Conservatorio Superior de Sevilla obtaining the Titulo Superior de Guitarra with Professor Josefina Calero. In 1998 he was the first guitarist to gain a scholarship by Fundacion La Caixa-British Council to study a Masters Degree at the London College of Music with guitarist Carlos Bonell. Later he moved to the Guildhall School of Music where he earned a Postgraduate Diploma and a Masters with guitarists Robert Brightmore, David Miller and the composer Mathew King. He won the Portallion Solo Guitar Prize at this school. He continued his studies at Universität Mozarteum in Salzburg with professor Isabel Siewers. While at Mozarteum, he also took studies at Arizona State University doing a Doctorate in Musical Arts under the direction of guitarist Frank Koonce. He was also an assistant teacher at this university. In 2004 he began his composition studies with Adriana Hölszky and Andre Ruschkowski at Mozarteum finishing his Masters degree at this school with Reinhard Febel. He also studied composition with Alexander Müllenbach at Luxemburg Consevatoire.
He has received guitar master classes from D. Russell, M. Barrueco, A. Diaz, R. Aussel, J.L. Rodrigo, J. Clerch, J. Cardoso, Roland Dyens, etc. As a composer, he attended masterclasses and workshops from S. Sciarrino, K. Schwertsik, D. Schnebel, C. Halffter, T. Marco, A. Posadas, J. Kaipainen and J. Tiensuu among others. He was the youngest guitar professor at Conservatorio Profesional de Ceuta during 94-95 and during 95-98 he was teaching at Conservatorio Elemental de Lucena, both in Spain. In 1998, during the celebration of the centenary of the poet Garcia Lorca, he worked with the theatre company Boardwalk in Lorca´s play “Bloodwedding”, where he included some compositions of his own. The same year, he participated in the English film “Maestro”. He also included his music in the film “Du bist Perfect”. For two years, he directed the contemporary music radio program “Die Nymphe” at the Radiofabrik in Salzburg. In 2007, he composed the music for the 300 anniversary of the Kollegienkirche in Salzburg. Since 2009 he is an artistic advisor of the Microtonal Music Society in Austria, giving seminars about his microtonal guitar at Escuela Reina Sofia in Madrid, St. Petersburg Conservatoire in Russia, Guildhall School of Music in London, Yong Siew Toh Conservatory in Singapore, etc.  
He has played solo concerts, in chamber music groups or with orchestra in Spain, France, UK, Italy, Swizerland, Belgium, Germany, Austria, Finland and USA. As a composer, he participated at the IV and V Bolivar Hall Guitar Festival London, Guildhall Contemporary Music Festival, Salzburg Strings Festival, Mozart Ante Portas Salzburg, West-Östlicher Einklang Symposium 2007, Stadtfestwoche Hallein 2007, stART 2007, Rocník Medzinárodného Festivalu Banska Bystrica, IG Nacht der Komponisten Austria, New Faces New Dances 2008 Salzburg, Österreichische Woche der Mikrotonale Musik, Internationales Gitarren-Festival Hallein, Sävellyspaja-Avanti! 2009, Spanish Evenings in San Petersburg, Expo 2010 Shanghai, University of Santo Tomas Guitarra 2010 Manila, etc. He has been awarded at Foret d´Orleans Festival (France) and at Festival Internacional de Velez-Malaga (Spain). He has been composer in residence from the Austrian government in 2010. 
His music has been conducted by D. Russell-Davies, S. Fontanelli, T. Ceccherini, J. Kalitzke (with OENM), Hannu Lintu (with Avanti Chamber Orchestra), Alexis Soriano (with S. Petersburg Symphony Orchestra), Hansjörg Schellenberger (with Sinfónica de Sevilla), Konstantin Hiller and C. Chamorro among others. His compositions have been broadcasted and recorded by ORF in Austria. He publishes his music for Doblinger Verlag.
He has written for different music groups; including solo, chamber music, orchestral, theater plays, choreographies and two chamber operas (“Adán de Eva” commissioned and performed regularly by El Cimarron Ensemble and “Don Quijotes Dulcinea” commissioned by the Passau Festspiele 2010 in Germany).
Web: http://www.castilla-avila.com/biography-Agustin-Castilla-Avila.html (2011)