A group of people escapes to a cabin in a rainy mountain forest, and the poem asks us to hear the place as music. The first stanza sets the scene: cedars "sigh," ferns seem to murmur a quiet lament, and the glow of the fire's embers is called a "baritone." That sound-word matters, because it suggests the fire is calming the noisy worries of "yesterday's business" rather than just warming the room.
In the second stanza, the music becomes the main idea. Breathing, leaves, rain on the tin roof, and wind all become instruments in an orchestra. The speaker finishes by describing their own stay as an adagio, a slow musical passage, resting inside a larger "green sonata." The feeling is peaceful and grateful. The speaker doesn't fight the forest or try to stand out from it, but quietly fits in as one more part of the piece.