This dissertation is a commentary upon five scores presented as a portfolio of research by musical composition. Background My compositional work prior to 2004 arose from neo-classical techniques, in a familiar-sounding tonal musical language. The works of the portfolio seek to depart from this. A post-modem view of musical language is that it may embrace multifarious sound-worlds, directly or obliquely referring to music of previous ages - using language as material. The way in which such material is presented is through structure, and this may exert as much influence on the style as do the harmony, melody and rhythm. Originality in music can be defined as the individuality of a composer's technique, (as opposed to merely the external effec...