This scoping review addresses peer-reviewed research on musical interaction with children and young people with severe/profound intellectual and multiple disabilities (S/PIMD). Twenty-five articles published between the years 2000 and 2020 met the inclusion criteria. A narrative synthesis was used to summarise and evaluate different features, including participant characteristics, study design and methods, type of musical interaction, the abilities and behaviours in focus, reported benefits, promising components of musical interaction, and quality appraisal of the studies. The results revealed a variation in participant characteristics and study designs, where small-sample descriptive case studies were most common. In terms of the type of musical interaction, active music therapy was the most commonly used approach, followed by technology-mediated and multisensory musical activities. In terms of abilities and behaviours, a large majority of the studies focused on social interaction and communication, followed by engagement, attention and affect. Six categories were identified as promising components of musical interaction: the responsivity of the interaction partner, singing songs, structure and predictability in the activities, long-term interventions, technology-mediated and multisensory musical activities, and a therapeutic alliance between interaction partners. Based on this review, we discuss future research and practical implications for musical interaction and music therapy for children and young people with S/PIMD.