Most human communication relies on experience, with few exceptions, one being music. Communicative musicality – the ability to communicate through music – can cross developmental, linguistic and cultural boundaries. Identifying the foundations of communicative musicality is a question of outstanding importance in cognitive science, as this ability has been suggested to support all human communication. Yet, to date, music is either studied in non-communicative contexts (i.e. with players or listeners in isolation) or not as a predisposition (i.e. focusing only on expert musicians). Building on the fact that it takes movement to make music, and that listeners move in response to music, MUSICOM tests whether the predisposition for communicative musicality is grounded in the capacity to instinctively communicate through movement. MUSICOM examines the behaviour and brain activity of laymen making music, and lay listeners responding to it, in real-time and interactive scenarios. A pillar of MUSICOM is the use of a validated novel experimental device offering the unique opportunity to allow everyone to make music and selectively control three fundamental musical features – rhythm, pitch and loudness – irrespective of training. Communicative musicality will be examined as a function of: (i) information transfer between a player and a listener, with gradually richer tasks moving from pure listening to listener-directed performance and joint music making; (ii) musical expertise, from non-musically-trained adults to expert musicians; and (iii) development, from children to adults. MUSICOM could change how we view and study music: shifting from an elite activity to a communicative predisposition accessible to everyone. MUSICOM will have groundbreaking implications for understanding the neurocognitive building blocks of human communication and its development. It will ultimately provide an empirical ground for testing the widespread use of music in clinical settings.