Analysis of The Roundel

A roundel is wrought as a ring or a starbright sphere,
     With craft of delight and with cunning of sound unsought,
   That the heart of the hearer may smile if to pleasure his ear
     A roundel is wrought.
    Its jewel of music is carven of all or of aught--
     Love, laughter, or mourning--remembrance of rapture or fear--
   That fancy may fashion to hang in the ear of thought.
    As a bird's quick song runs round, and the hearts in us hear
     Pause answer to pause, and again the same strain caught,
   So moves the device whence, round as a pearl or tear,
     A roundel is wrought.