This paper is based video data from a project called SALTMusic, for young children diagnosed as having "language delay." The interdisciplinary action-research project was co-delivered by speech and language therapists and early childhood arts practitioners, with children and their parents. Addressing a concern that children's lack of words places anxiety, guilt, and stress upon families, SALTMusic explored ways of engaging with children using minimum words, by focusing on playful encounters of bodies responding to a range of materials, objects, and sounds. In this paper, we consider two filmed events from this project. We explore these events through the theme of this special issue, with its emphasis on the "complex intermingling of knowledges" between children, their families, early years' arts practitioners, and speech therapists. We wish to think more deeply about what happens when adults talk less, and instead use space, sound, materials, and bodies to converse with toddlers. In particular, we turn to the dramaturgical notion of "complicité" in order to enlarge our understanding of communication and conversation towards a mutually transformative sense of unfolding collective action. In particular, we ask what the potential of the concept of "complicité" might offer early years' practice in an era of accountability, where the professionalization discourses of early childhood education are creeping into and infecting parenting discourses. We ask if the concept of "complicité" might help adults working with young children to resist the domination of word-oriented discourses that eclipse implicit, bodily, and materially attuned ways of relating to the young child.