Since Teasdale is only working with 18 lines, you can bet each word is there for a reason.
The first line does a lot of groundwork that sets up the rest of the poem. She presents us with this idea of Life having "loveliness to sell." Teasdale uses this extended metaphor (in this case, Life is a salesperson that wants to sell us some loveliness) throughout the poem.
The word sell is important.
If someone is selling you something, they want you to have it. Usually, the seller gets cash in return for their product.
In this case, life is selling loveliness, but the loveliness can't be bought with cash—the title of the poem tells us that this is a barter transaction.
Life wants to barter with you, to exchange loveliness for something besides cash (no cash, no checks, no credit cards, no PayPal, nothing).
At this point, we aren't sure what life wants in exchange, but let's stick a pin in that and come back to it later.
All beautiful and splendid things, Blue waves whitened on a cliff, Soaring fire that sways and sings, And children's faces looking up Holding wonder like a cup.
The rest of stanza 1 begins a catalog. The speaker introduces the list with a general description of what will follow: "All beautiful and splendid things."
It's like the introduction to a sales pitch: "Sure, we got cars. We got the best cars in the tri-state area! Everyone is a gem. Let me tell ya what we got."
Next come the specifics. We have three examples of loveliness in the first stanza: ocean, fire, and kids.
Teasdale's descriptions include lots of sensory details (details that incorporate one or more of the five senses—sight, sound, taste, smell, touch).
Line 3 gives us the color blue, but just as we are imagining the blue waves, they are "whitened" when they crash into a cliff.
The alliteration, those repeated W sounds, sort of mirror the movement and uniformity of the waves (notice how your mouth has to make the same shape twice to make those W sounds) and then everything changes with the hard C sound of cliff. The Ws crash into the C. Kind of a cool trick, right?
We have more alliteration in line 4. The repeated S sounds mirror the fire's swaying and singing. It helps to give the line the rhythmical feel of a dance.
Teasdale has also thrown in some personification here, giving fire the human characteristics of singing and dancing.
The last description of loveliness in stanza 1 is of "children's faces." Seems like things are starting to get a little sappy, right? When Shmoop starts reading about the smiling faces of small children, we assume that rainbows and unicorns can't be far behind.
But Teasdale short-circuits the sentimentality by ending the description with kind of a weird simile. She tells us that the children's faces hold wonder "like a cup." Hmmm. We haven't heard that before. Way to go, Sara. Nice save.
You probably noticed that some of the lines in the first stanza have very strong end rhymes. This poem follows a rhyme scheme of ABCBDD.
The rhymes in this poem aren't all that special ("thing" and "sing," "up" and "cup"), but they do make the poem sound very tight, controlled, and it reads pretty quickly. It almost feels like a little song or nursery rhyme.
To be fair, the rhyme scheme isn't the only thing responsible for the rhythmic feel of this one. Meter plays its part as well.
Some parts of "Barter" are written in a rhythmic form known as iambic tetrameter. It's what gives the poem that da DUM da DUM kind of a feel.
Listen: and children's faces looking up
So those iambs—an unstressed syllable followed by a stressed one (there are four iambs in our example)—along with the strict rhyme scheme, give this poem its musical sound and feel.