One can argue that understanding how a piece works makes you a better performer, and a better teacher of that piece. One can argue that understanding a piece of music makes you a better composer and arranger of music which has similar characteristics. One can argue that knowing how music works in general, through the intimate understanding of how pieces and passages work in particular, can make you a more effective music therapist. And finally, one can argue that understanding how music works makes you a better music scholar. Oh, and by the way--and this is for music majors--you have agreed to study music theory as part of the deal you made to get your music degree. And that is why music theory, in all its manifestations, is required study for all music majors.
Know that we teachers of music theory are concerned constantly with finding tools with which to understand music, and to facilitate your awareness of them. That is what music theory is all about. Keep these thoughts and observations in the forefront of your mind as you work through and practice the exercises. Good luck!
E-mail Pandel Collaros