Models of Algorithmic Composition in Prologue for String Quartet

Abstract

This paper presents an analysis of the algorithmic models used by the composer to generate the music of Prologue for string quartet. The project makes an homage to Lejaren Hiller’s pioneer work in the area of computer-aided composition. A relevant difference of this project in relation to previous projects in the area of algorithmic composition is the emphasis given to the rhythm parameter, which, in this case, is the main conductor of the narrative structure of the piece. The techniques employed revisit classical models, like Markov chains and combinatorial and permutation analysis, but also make clear the contribution of pre-compositional decisions by the composer, and the influence of mappings and numerical data generation with aleatory methods. Notice that this project uses the flexible properties and intrinsic non-tonal relations of hexachordal collections, particularly the whole tone collections. Equally important is the appropriation that the project makes of models inspired by baroque techniques, like, in this case, the four voices invertible counterpoint and the rhythmic variations by diminution.