It’s a trick question! They coexist in a reciprocal process where one underpins the other

This concept is central to my approach to music therapy.  I have often read (Bruscia, 1998; Wigram, 2004; Pavlicevic, 2000, AMTA, 2014) and heard many music therapists in conversation or keynote papers pinpoint aesthetics as a key difference between performance and music therapy as MT doesn't expect the same standard of beauty. That is, music in a therapeutic setting may not sound as nice as concert music.

Others (Ansdell, 2005; Lee 2003; Aigen, 2002) observe the clinical relationship to have its own aesthetic  drivers which play a significant role in shaping the music as it develops within the session where “beauty is a quality that can happen between people, not just a quality of a musical object” (Ansdell, 2005 p.216). The aesthetic qualities of the therapeutic relationship guide the music therapist’s application of music, acting as an intermediary between the musical identities of the therapist and the client within the clinical setting.