Shakespeare's language is a good example of euphony: pleasant, musical sounds in harmony, as with “To-morrow, and to-morrow, and to-morrow / Creeps in this petty pace from day to day.”
Use euphony to describe music or poetry. To understand it, break it down: eu- means good; phon- means sound or voice. Of course, just as beauty is in the eye of the beholder, euphony is in the ear of the listener — it's subjective. Kids and their parents rarely find euphony in the same song.