The iso principle is a commonly used and well known technique among music therapists.  The iso principle is “a technique by which music is matched with the mood of a client, then gradually altered to affect the desired mood state.  This technique can also be used to affect physiological responses such as heart rate and blood pressure.” (Davis, Gfeller, & Thaut, 2008).  Utilizing the iso principle can be an extremely effective tool to alter emotional symptoms (mood) and physic