Music therapist Kenneth Bruscia stated “A "model" is a comprehensive approach to assessment, treatment, and evaluation that includes theoretical principles, clinical indications and contraindications, goals, methodological guidelines and specifications, and the characteristic use of certain procedural sequences and techniques.” In the literature, the terms model, orientation, or approach might be encountered and may have slightly different meanings. Regardless, music therapists use both psychology models and models specific to music therapy. The theories these models are based on include beliefs about human needs, causes of distress, and how humans grow or heal.