Actually, how do you separate different instrument sounds as far as "melodies" go? Coming from a classical background, I always imagine the melodic sounds as doppelgängers for, say, lower brass, upper brass and woodwinds, and string of various tones. I do get stuck often in this area, since I feel I need to break open the theory books and revert back to 4-part harmonies. Is this something you've struggled with, and if so, how do you get passed this?
P.S., white noise is white hot