This chapter summarizes research on the effects of musical training on brain function, brain connectivity, and brain structure. First, it addresses factors inducing and continuously driving brain plasticity in dedicated musicians, arguing that prolonged goal-directed practice, multisensory–motor integration, high arousal, and emotional and social rewards contribute to these plasticity-induced brain adaptations. Subsequently, the chapter briefly reviews the neuroanatomy and neurophysiology underpinning musical activities by focusing on motor planning and motor control. A review of the literature on functional changes in brain activation and brain connectivity along with the acquisition of musical skills is provided. Structural adaptions in the gray matter of the brain and in fiber tract density associated with music learning are critically discussed. Finally, the chapter addresses the phenomenon of de-expertise, when intensive music-making induces dysfunctional changes of brain networks.