Treize Etudes Pour L?Orchestre is a thirteen-movement symphonic work for full contemporary orchestra. The purpose of this work has been to develop a sonic exploration of textural possibilities through the orchestral medium. The motivic materials of the whole piece were first utilized in pieces for one piano, piano and cello and two pianos combinations These smaller pieces ahs been included in the appendix section of this work. The orchestral work does not represent an orchestration of the smaller pieces, but an expansion of the material into different textural studies. Preparation for this work includes the study of twelve different bird sounds, first recorded and later musically transcribed to create thematic materials and secondary materials for this work; the study of production of fabric of sounds representing color spectrums and intensity through sound tapestries, and the sonic representation of water, a starry dark night and the jungle. The Treize Etudes Pour L?Orchestre is formally a through-composed work. The different musical materials created as motive unity of the whole work have been developed throughout it by means of using a variety of compositional devices and techniques including Schoenberg?s Klangfarbenmelodie, Messiaen?s ?Language Musicale?, Ives? quadraphonic effect, and Samuel Adler?s sound curtain technique, and, the use of folk-like materials; all within the parameters of acoustic instrumentation.