This thesis comprises six new musical works composed between 2008 and 2015: ‘Struction (how I attempted to get the thoughts in my head into your head using only five instruments, five instrumentalists, metronome sound and MIDI') for amplified ensemble and pre-recorded soundtrack (2011); ‘My Life in Ventriloquism' for solo clarinet and pre-recorded soundtrack (2012); ‘Nightmusic' for solo violin (2012); ‘Replaceable Parts for the Irreplaceable You' for ensemble, pre-recorded soundtrack and video (2013); ‘Espial', a video work featuring string quartet (2014); and ‘Elbow Room' for amplified ensemble, pre-recorded soundtrack and video (2014). The works are presented in this thesis as musical scores (and other performance materials), accompanied by audio-visual documentation of performances. As a whole, these compositions reflect a period of practice-as-research into the role of metapraxis in musical performance and how it can be used to help convey non-musical thought through instrumental music. A commentary on this portfolio of new compositions begins by discussing two influential works — Mauricio Kagel's ‘Match' (1964) and ‘Failing: A Difficult Piece for Solo String Bass' (1975) by Tom Johnson — before examining each new work in detail in order to explicate the research and creative processes that led to their composition, to exteriorize a personal working practice and to document the reflection-on-practice which has furthered this research. The commentary details how I was able to write music on a variety of topics, including authority, technology and place, and concludes with some ideas for further research.