Musicians’ brains exhibit distinct neuroanatomical and neurophysiological adaptations due to their intensive and specialized training. These adaptations are a result of neuroplasticity, the brain’s remarkable ability to change structurally and functionally in response to experience. This chapter explores both functional and structural plasticity, detailing how expertise-dependent modifications occur in musicians’ neural networks. Cross-sectional and longitudinal studies highlight significant changes in auditory, motor, and multimodal integration systems, demonstrating enhanced efficiency in sensory processing, motor control, and cognitive functions. The auditory system of musicians is particularly plastic, showing greater cortical representation and stronger connectivity patterns. Sensorimotor adaptations reflect optimized motor execution, with musicians exhibiting specialized audio-motor couplings that facilitate skilled performance. These modifications also extend to cognitive domains, suggesting transfer effects of musical expertise to language processing, executive functions, and memory. The chapter further discusses the medical applications of music, including its role in neurological rehabilitation, stroke recovery, and cognitive aging. Music-based interventions have shown promising effects in delaying cognitive decline and enhancing brain resilience, supporting the concept of brain reserve in aging populations. The unique interaction between genetic predispositions and environmental influences is also explored, highlighting how music training may reinforce neural efficiency and delay neurodegenerative processes. In conclusion, musicians provide a compelling model for studying expertise-driven brain plasticity. Their enhanced neuroanatomical and neurophysiological profiles not only illuminate the principles of neural adaptation but also offer insights into broader applications in health, education, and cognitive science.