The Rime of the Ancient Mariner
If The Rime of the Ancient Mariner were a song, it would have to be a country song. The comparison between the ballad and country music is appropriate because both are popular folk genres. If you're like us and listen to country music radio, you'll notice that a lot of the songs tell a story. These stories might not be as long as The Rime of the Ancient Mariner, but the idea is the same. The singer wants to tell you about some hard times and then wrap things up with a moral at the end. The Mariner himself is essentially just his age's version of a trucker, except his open road is the ocean.
The stanzas in the poem are meant to be small and easily digestible, and, if you read it straight through, you'll notice lots of repetition between sections. This repetition helps us pick up changes in the plot. For example, in Part I Coleridge describes in very plain language how the sun rises on the left and setting on right, which tells us that the boat is going south. We might be thinking that this detail is completely irrelevant: of course the sun rises and sets! But then in Part II, he says that the sun is rising on the right instead, which means the ship has changed direction and is now heading up north. It's a whole lot more interesting than just saying, "And then we started sailing north again," and it establishes a consistent tone when you hear it repeated.
Another potential comparison between this poem and country music is that both the narrator and the Mariner use what would at that point have been considered "folksy" language. They employ traditional-sounding words like "biddeth" and "uprist," and they use alliteration in many places. Finally, the simple rhyme scheme (ABCB) is exactly the same that you'll find in many if not most rhyming songs, country or otherwise. The point is always to make you pay attention to the lyrics without losing hold of the song.