THE chief characteristic of rhythm perception is the subjective grouping of objectively separate events. In a rhythmic sequence of identical tone-bursts, adults do not perceive the repetition of a single sound, but a recurring configuration which has temporal form. Such a sequence is organised according to the Gestalt law of proximity1,2. Organisation of temporal form has never been studied systematically in pre-verbal infants. We present here results suggesting a precocious achievement of this function and contrasting with previous research3 which failed to demonstrate organisation of spatial form by babies in accordance with the proximity law.