Paradoja: Concerto for Orchestra consists of three contrasting movements: slow, fast, slow (Paradoja = "paradox," Sp.). These movements are framed by a motif that opens and closes each of them, and connects them all. This framing motif is based on an alternation between a rhythmical pattern in the bass drum, and a melody sung by a boy mezzo-soprano, both over a string pedal. The first movement, Lamentos (Sorrows), is dramatic in character; it goes from simple to complex in its orchestration, harmony, texture, dynamics and tempo changes. The second movement, Algarabía (Tangle), reflects a festive affection; it presents a contrast to the first in character, tempo and spirit. The third movement, Sosiego (Serenity) provides a peaceful ending to the piece; it is lighter than the other two movements in texture and orchestration. The general harmonic language of Paradoja: Concerto for Orchestra is non-tonal yet centric, with surface references to functional harmony. However, the pitch content varies from movement to movement. The first movement is highly chromatic and based in the twelve-tone collection. The melodies are created by a combination of small pitch-class sets and sometimes are broken down and distributed among different instruments. Harmony is the result of the juxtaposition and counterpoint of these melodies, which vertically reiterate the same cells or creates new sets. The second movement is based on smaller collections than the first, and it is less chromatic. Contrast is often created by changing the collections or simply transposing them. The third movement is the most homophonic and the least chromatic of all three. It is based on a combination and juxtaposition of diatonic and non-diatonic collections that interact with each other. Paradoja: Concerto for Orchestra is examined in two broad categories. The first is a structural analysis, which includes details of form and pitch selection such as pitch collections, set classes and motives. The second is a stylistic analysis, which includes aspects of style such as rhythm, orchestration. The conclusion refers to the influence of historical models and aspects of the compositional process. Both the structural and stylistic analyses demonstrate how I have tried to merge diverse stylistic music elements to obtain a new personal idiom. / Music Composition / Accompanied by one .pdf score: Paradoja: Concerto for Orchestra: Full Orchestral Score.