In this paper, we present a pitch space based musical interface approach. A pitch space arranges tones in a way that meaningful tone combinations can be easily generated. Using a touch sensitive surface or a 3D-Joystick a player can move through the pitch space and create the desired sound by selecting tones. The more optimal the tones are geometrically arranged, the less control parameters are required to move through the space and to select the desired pitches. For this the quality of pitch space based musical interfaces depends on two factors: 1. the way how the tones are organized within the pitch space and 2. the way how the parameters of a given controller are used to move through the space and to select pitches. This paper presents a musical interface based on a tonal pitch space derived from a four dimensional model found by the music psychologists , . The proposed pitch space particularly eases the creation of tonal harmonic music. Simultaneously it outlines music psychological and theoretical principles of music.