Thomas Randolph's poem entitled "The Song" concentrates a great deal on nature.
Personification is giving human characteristics to non-human things.
There are several examples of personification in the poem. The first thing that is personified is Music, called "thou queen of souls," which the speaker encourages to "get up and string Thy powerful lute, and some sad requiem sing..."
There are other things personified as well. They are:
"the pine to dance, the oak his roots forgo
The holm and aged elm to foot it too;
Myrtles shall caper, lofty cedars run,
and call the courtly palm to make up one.
The sense is that different parts of the forest, particularly trees of various kinds, dance to the sound of music, and then, upon hearing a sad note, become trees, fixed in place and unmoving.
For your reference, "caper" means to skip or dance about; "foot it," I believe, would mean to tap in time to the music, or to dance.