Yeats has one of the most recognizable sounds of any modernist poet, and you can almost catch it right away with his loose tetrameter and ABAB rhyme scheme. But even though he has these strict formal boundaries on his poetry, he somehow manages to make it sound as if he's talking to us in normal (albeit still pretty) language.
At the poem's beginning, he gets our attention by saying, "I have met them at the close of day/ Coming with vivid faces" (1-2). Now the phrase "close of day" is a clever way of saying that the day is getting toward it's end, but also that the businesses are shutting down and people are closing up and heading home. When you really focus on the sound of "the close of day," though, you also get a sense of how Yeats likes to change one of two words in his phrasing to give his language a nice musical quality.
Another thing you usually get with Yeats is something that sounds pretty, but actually describes something horrifying. For example, at the end of stanza one he says, "All changed, changed utterly: / A Terrible beauty is born" (15-16). Now what he's actually talking about is people being executed. But Yeats has this way of still making death and suffering sound like it's part of some larger more beautiful plan. It's as if everything can be beautiful once it exists in poetry, and Yeats' sound does a great job of conveying this.