Final answer:
In Joyce Carol Oates' 'Where Are You Going, Where Have You Been?', music is what made everything good for Connie and something she could depend on.
Step-by-step explanation:
In the short story "Where Are You Going, Where Have You Been?" by Joyce Carol Oates, the element that "made everything so good" for the protagonist, Connie, and was "something to depend on" was music. Connie identifies with the music she listens to, which reflects her emotions and aspirations. Music offers her an escape and a way to connect with her inner self, serving as a reliable source of comfort amidst her feelings of unhappiness and rebellion.