At present, there is growing scientific evidence of music's powerful, positive influence on the neurological, cognitive, and social-emotional development of all children. At the same time, a flurry of new studies now show that extensive, deliberate, and deep practice supported by an ability growth mindset--and not a fixed degree of talent--is the primary predictor of future expertise in music, as it is in other disciplines. This article argues that parents and educators today must therefore shed the outdated myths and misconceptions of predetermined talent in order to embrace substantial development of "acquired expertise" in music as an agent for engaging and optimizing every child's capacity to learn across many areas of a school's academic and social curriculum. Thus, music education policy stakeholders need to support innovative teaching practices that are free of lingering explicit, implicit, or unconscious assumptions of "innate talent" in order to craft and implement public education policies that will lead to early, ongoing, and equitable access to an intensive study of music that is aligned with the evolving twenty-first-century views of this area's essential contribution to all children's human development. (Contains 15 tables, 7 figures, and 40 notes.)