This chapter explores the integration of sociocultural perspectives in music therapy to situate the “best interests of the child” within the broader context of cultural and societal influences. Challenging traditional, static views of childhood, the chapter emphasizes the need for a nuanced understanding of childhood as a socially constructed concept shaped by diverse cultural and historical contexts. It argues that sociocultural factors, including norms around child-rearing, education, and family structures, must inform decisions about a child’s well-being and health. In addition to situating the best interest principle within sociocultural contexts, the chapter critically examines developments in music therapy literature that address traditional approaches. These include emerging perspectives such as posthumanism, disability studies, and post-ableism, which encourage a critical reevaluation of conventional child development paradigms. Advocates of these perspectives emphasize the importance of viewing childhood as dynamic and context-dependent, highlighting how cultural variations influence what is deemed in a child’s best interest. The chapter underscores the necessity of critical thinking and interdisciplinary approaches in music therapy to address sociocultural complexities. By doing so, it highlights how music therapy can contribute to a culturally sensitive understanding of childhood and child development, ensuring that practices are inclusive, adaptable, and reflective of the diverse needs of children in varying sociocultural contexts.