George Perle’s Twelve–Tone Tonality: some developments for CAC using PWGL

This paper presents a description and some developments on Perle’s theory and compositional system known as Twelve-Tone Tonality, a system that, because of its characteristics and fundamentals, is currently associated with Schoenberg dodecaphonic system. Some research has been made in the last few decades in order to develop his model in a Computer Assisted Composition (CAC) environment. After some efforts in order to analyse these prototypes, we realize that in general they were discontinued or outdated. A three-scope proposal is so outlined: Firstly, to simplify the grasp of a system that presents an easily understandable starting premise but afterwards enters a world of unending lists and arrays of letters and numbers; Secondly, to present the implementation process already started using PWGL [1] (see Laurson, 1996; Laurson, 2003; Laurson, 2009). Finally, the model is applied in a short original compositional work, and it is presented and analysed emphasizing the standpoints properties of the system. Some further considerations were made regarding the continuity of this project where the construction of a dedicated PWGL library of Perle’s model reveals a pre-compositional necessary tool. PWGL software was selected due to its specific fitting features: it is based on Common Lisp - perfectly powerful and suitable to process lists of integers — and it is specialized in CAC