Medusa is a nomad instrumental and installation device designed to support a solo cello performance which incorporates specific sonic and architectural characteristics of the place where it is installed and performed. Addressing questions of site-specificity both in the installation setup and the musical performance, this electroacoustic system aims for a “sonic transfiguration” of the cello´s body when in contact with the place hosting its performance. The solo concert “feeds” and activates a stand-alone installation.