The hills are alive with the sound of music, and we have more than just the Von Trapp family to thank for it. Music appears in "The Passionate Shepherd" literally and rhythmically, and it helps contribute to the lighthearted, lively countryside being portrayed by the speaker.
Line 1: Count the consonants that commonly occur and you shall see that some sounds are alliterated abundantly and appear in many more measures than others. As in many other poems, Marlowe makes use of alliteration, consonance, and assonance in this one. The first instance of this appears in line 1, with the L sound alliterating in "live" and "love." The L sound, among many others, follows the reader through the poem and adds a musicality to the lyrics when read out loud.
Lines 2-4: We see more sound play here, too. Read the lines aloud to yourself and you'll see what we mean.
Lines 5-8: Here we're paying more attention to the kinds of sounds Marlowe chooses to repeat rather than the fact that he repeats them. The sounds repeated in the second stanza, the W of "we will", the S of "seeing the Shepherds", the M of "melodious" and "madrigals", and the ever-present L sound are not harsh, but light and breathy. By choosing to repeat these sounds as opposed to ones that have a little more bite to them (like the hard C or D sounds), Marlowe adds to both the musicality of his poetry and the lightness of its tone.
Line 8: The birds in this line are literally singing, and not just any normal bird calls—they're singing madrigals. What's a madrigal, you say? Well, it's not your average tune. Madrigals are fancy songs written for many voices singing in harmony and the arrangements are usually very complex. They were very popular in the Renaissance and clearly Marlowe's birds have, most impressively, picked up on the trend.
Line 21: The image of the shepherds swains dancing and singing is another literal invocation of music. Country festivals often appear in pastoral poetry and are stereotypically associated with lively games, community bonding, and obscure country folk traditions, many of which involve music and dancing.