This contribution combines techniques for sound synthesis and spatial reproduction for a joint synthesis of the sound production and sound propagation properties of virtual string instruments. The generated sound field is reproduced on a massive multichannel loudspeaker system using wave field synthesis techniques. From physical descriptions of string vibrations and sound waves by partial differential equations follows an algorithmic procedure for synthesis-driven wave field reproduction. Its processing steps are derived by mathematical analysis and signal processing principles. Three different building blocks are addressed: The simulation of string vibrations, a model for the radiation pattern of the generated acoustical waves, and the determination of the driving signals for the multichannel loudspeaker array. The proposed method allows the spatial reproduction of synthetic spatial sound without the need for pre-recorded or pre-synthesized source tracks.