This paper presents a technological platform aiming at analyzing and improving musicians' sound-gesture relationships. The conceptual foundations of the platform were driven by our latest research results, which highlight the close intertwining between sound quality and motor behavior among professional cellists. In particular, the results revealed that the cellists' timbre was consistently altered when they were deprived of their fine postural movements, such as torso swaying or head nodding. In a reciprocal way, we are now interested in investigating how subtle real time deformations of their natural timbre may affect their functional behavior. Besides the instrumental timbre, the platform should also enable to assess the musicians' motion/space intrications by modifying their surrounding acoustic space in an ecological way. After two years of development, we here present a mature architecture of our multimodal tool through the prism of these investigations. Such an architecture is particularly suitable for designing complex sound synthesis protocols involving the musicians' kinesphere perception related to the musical structure.