Language- and music-readiness are demonstrated as related within comparative neuroprimatology by elaborating three hypotheses concerning music-readiness (MR): The (musicological) rhythm-first hypothesis (MR-1), the combinatoriality hypothesis (MR-2), and the socio-affect-cohesion hypothesis (MR-3). MR-1 states that rhythm precedes evolutionarily melody and tonality. MR-2 states that complex imitation and fractionation within the expanding spiral of the mirror system/complex imitation hypothesis (MS/CIH) lead to the combinatorial capacities of rhythm necessary for building up a musical lexicon and complex structures; and rhythm, in connection with repetition (...) and variation, scaffolds both musical form and content. MR-3 states that music’s main evolutionary function is to self-induce affective states in individuals to cope with distress; rhythm, in particular isochrony, provides a temporal framework to support movement synchronization, inducing shared affective states in group members, which in turn enhances group cohesion. This document reviews current behavioural and neurocognitive research relevant to the comparative neuroprimatology of music-readiness. It further proposes to extend MS/CIH through the evolution of the relationship of the language- and music-ready brain, by comparing “affective rhythm” and prosody – i.e. by comparatively approaching the language- and music-emotion link in neuroprimatology. (shrink)