Arrangement has always played an essential part of transmitting, preserving and disseminating works in the musical practice of both ‘high art’ and popular music. However, at present it is rarely practised in electroacoustic music, which can partly be explained by the nature of electronic technology and current thinking about authenticity. Despite this context, there are benefits to performance opportunities through the diversity created by arrangement; therefore, the process of adapting the electroacoustics of Scelsi's Aitsi is explored. The work offers this opportunity, since it lacks precision in its musical documentation, has received a number of quite different renditions and shows ontological malleability as it exists in another form, Scelsi's Fifth String Quartet. The new electroacoustic adaptation exploits Max/MSP software to extend the electroacoustic treatment of the piano beyond previous interpretations, whilst attempting to remain consistent with the aesthetic of the work. The article aims to encourage the composition and adaptations of works that afford performers interpretative licence with the electroacoustics in order to promote the distinctive and evanescent nature of mixed acoustic-electroacoustic works in concert performance, and encourage its continuation through an evolving performing tradition.