Two classrooms of diverse 5-year-old children were set the task of exploring ways of realising music invention through the semiotic import of composing resources. In both a rural and an inner-urban setting in Australia, children demonstrated syncretism in bilingual practices in communication. Visual multimodal analysis demonstrated how children were enabled to import music modes or conceptual elements of music within the overriding mode of music during music improvisation. By giving status to these minority literacies through music invention, children imported semiotic resources as elements of music (music modes) and cultural meanings across borders and contexts. These case studies investigated new ways of engaging diverse students beginning school. They explored the interconnectedness of cultures increasingly circumscribed in realities of classroom music and literacy. Conceptual understanding was established across modes of linguistics and music in both a rural and an inner-urban setting in Australia. Using social semiotic multimodal theory, the studies documented ways children create literacy forms through transmodal redesign of situated practices in music invention. Two focal composing activities, one from each setting, were selected as thematic cases. The first demonstrated how conceptual understanding was established across modes from linguistic (picture book literacy) to audio (music invention) and the second, from audio to verbal linguistics, through children's music invention. The pedagogical implications of a conceptual framework, the Space of Music Dialogue, were demonstrated in this study. Through this multimodal framework, educators can explore the full extent of student voices in classrooms and evaluate their growth in conceptual understanding in music and linguistics.