Thanks to the development of new technology, musical instruments are no more tied to their existing acoustic or technical limitations as almost all parameters can be augmented or modified in real time. An increasing number of composers, performers, and computer programmers have thus become interested in different ways of "supersizing" acoustic instruments in order to open up previously-unheard instrumental sounds. This leads us to the question of what constitutes a super instrument and what challenges does it pose aesthetically and technically? This work explores the effects that super instruments have on the identity of a given solo instrument, on the identity of a composition and on the experience of performing this kind of repertoire. The super instrument comes to be defined as a bundle of more than one instrumental lines that achieve a coherent overall identity when generated in real time. On the basis of my own personal experience of performing the works discussed in this dissertation, super instruments vary a great deal but each has a transformative effect on the identity and performance practice of the pianist. This discussion approaches the topic from the viewpoint of contemporary keyboard music, showcasing examples of super instrument compositions of the 21st century. Thus, the main purposes of this practise based research project is to explore the essence and role of piano or toy piano in a super instrument constellation, as well as the performer's role as a "super instrumentalist". I consider these issues in relation to case studies drawn from my own compositional work and a selection of works composed by Karlheinz Essl and Jeff Brown. Appendix: Contents of CD and DVD CD Track 1: Maria Kallionpää: Zusammenbindenbinden.Winden? –Hommage a Schumann. Tuuli Lempa, piano; Marko Myöhänen, electronics. Helsinki 2012. Track 2: Maria Kallionpää: Trinity Mania. Maria Kallionpää, piano; Florian Hartlieb, electronics. Vienna 2010. DVD Track 1: Karlheinz Essl: Sequitur V. Maria Kallionpää, toy piano; Karlheinz Essl, electronics</p
