The chapter provides a summary of the evolution of music therapy, starting from its initial definition, which characterizes the discipline as predominantly relational intervention. The scientific evolution of music therapy has expanded its applications, leading to a redefinition of the underlying therapeutic models and rationale. The essential points defining music intervention as potentially therapeutic are outlined in the initial part of the work. This leads to a potential extension of music therapy techniques, also considering interventions whose rationale lies not only in relational but also in neuroscientific domains. Consequently, some technologically mediated interventions within the rehabilitative context are highlighted, as well as interventions based on musical listening, whose therapeutic value can be attributed to specific characteristics of the musical mediator. This also implies reflections on the training and professional profile of the music therapist. Considering the above, a new possible definition of music therapy emerges, taking into account previous definitions but shaping interventions based on specific theoretical and applied criteria. This results in a more rigorous distinction between the concept of therapy with music and generic musical intervention. Finally, the chapter proposes and discusses the applied and research perspectives that are characterizing the rapid evolution of the discipline.