"Barter" is from Teasdale's book titled Love Songs. Several of the poems in the collection are titled as songs. It's a pretty safe bet that music, sound, and song were key elements for Teasdale thematically and in terms of her creative strategy (how she put her poems together). Music and song come up in "Barter" as well. No big surprise, really—which is too bad. Shmoop loves surprises. We even like pop quizzes. We're that sick.
Line 4: What do you think of when you think of fire? Shmoop bets you said hot. Those of you that didn't say hot probably said barbeque. If you are in group 2, time to take a snack break.
The point is Teasdale doesn't go with the typical descriptions and associations for fire. Flames are not jumping or crackling. In line 4, the fire "sways and sings." That's a pretty musical fire.
Teasdale finds the beauty of dance and music even in the movement and sound of life's most basic elements. Looks like she's already bought what Life's sellin'.
Line 8: This line talks directly about music. Music is one of the lovely things that life has to offer. The line is also a simile: "Music like a curve of gold." The line has a rhythmic feel that fits with the content, but the comparison to a "curve of gold" is unexpected.
Gold is beautiful, valuable, and the description of a curve brings to mind a ring and all the symbolic weight a ring of gold carries (no, not like The Lord of the Rings, more like a wedding ring). So, in a way, the comparison of music to gold kind of makes sense—it gives a value and importance to music in a visually and symbolically interesting way.
Line 15: This line describes a peaceful mental or emotional state as, "one white singing hour." Yup. More music.
This description also seems a bit unusual at first. But if we take a closer look, it makes its own kind of sense. We have white, which often symbolically represents purity. So, this hour is pure, in the sense that it is untainted by anything. None of life's unpleasantness or cruelty is present. It's like that first day of school feeling—no failed tests or cafeteria drama to pull you down.
The fact that "peace" is a "singing hour" is another example of how important music and song are to Teasdale. It is in a sense of music and song that her speaker finds "peace."