Neuroscientists have worked for over two decades to understand how the brain processes music, affects emotions, and changes brain development. Much of this research has been based on a model that compares the brain function of participants classified as musicians and nonmusicians. This body of knowledge reveals a large number of benefits from music education including improvements in memory, language acquisition, executive function, and brain plasticity. These findings offer the beginnings of an evidence-based argument in favor of music education for every child. Yet if the potential of this research is to be leveraged for this purpose, music educators need to know the type, period, and age range for music education that has been shown to affect positive, measurable, and enduring change in brain development. This article explores the criteria used to define musician and suggests ways these criteria could be used to advocate for specific developments in music education curricula.