A Theremin is essentially an electronic synthesizer, which reacts to the distance between a hand and an antenna. The music is created from an internal oscillator which reacts to an induction field, when it is disturbed by the layer. In the Thereminic room, small groups of pupils with serious impairments will be able to create music expressions together, by interacting in various ways with the different antennas and the accelerometer. In this way the participants will be inspired to move in rhythms and patterns, thus promoting physical exercise for the pupils involved. In what follows two ideas are presented, interfacing the room with the antennas and defining appropriate variables for the system based on the players' movements, designing an interface to help teachers to create willing sound by setting variables in the system in the room. The concepts are proposed based on an existing system. The outcome of the thesis is a design solution to assign proper note values to a distance which make it possible to play different set scales based on the players movement in the room, in addition, the suggested idiomatic user interface design could map the configuration of the four antennas and their activities to the appropriate Musical Instrument Digital Interface (MIDI) signals for the software synthesizer.