My dissertation is an investigation of the rhythm and fills presets on the Mellotron MKII (1964) through a series of compositions. All the sounds used in these compositions are Mellotron sounds from the MKII, which were edited and arranged using a digital audio workstation (DAW). In this study I dissect the instrument, and outline every aspect of the rhythms and fills presets. In the process, I develop an expanded model of performance practice on the instrument, presenting new playing and compositional possibilities. These are made possible through comprehensively documented analysis of the instrument’s sample set and the tempo, key and pitch permutations achievable through its on-board modulation controls. The Mellotron is significant because it was among the first samplers in history, and quickly became an iconic sound, woven into the cultural fabric of 1960s British pop. The Mellotron was used on The Beatles’ ‘Strawberry Fields Forever’, Led Zeppelin’s ‘Kashmir’, David Bowie’s ‘Space Oddity’, and The Rolling Stones’ ‘2000 Light Years From Home’, to name a few. While the Mellotron is featured on these famous songs, it has never been used as a solo instrument for a long form composition, nor have its samples ever been transcribed. The study takes a reflexive approach, using journals compiled through the composition process to support the development of new Mellotron techniques and compositions. The compositions presented in this study establish and demonstrate the Mellotron’s capability for extended solo work. The new techniques presented here make the Mellotron more practical for improvisation, composition and performance in new musical contexts. Additionally, the research expands scholarly/educational literature on electromechanical keyboards, providing in-depth technical, historical and musical data on the Mellotron. / Art History, Visual Arts and Musicology / M. Mus. (Music)