Noyes liked to keep his poetic style pretty traditional, and that really shows in this poem. The poem is broken up into even, regular chunks, and the pattern of the rhymes doesn't change at all from one part to the next.
The first thing to notice about the form of this poem is the way the lines are divided up. The stanzas (those are like the paragraphs in a poem) are always six lines long. You'll also notice when you look at the poem that the fourth and fifth line in every stanza is about half as long as the other lines.
The pattern of the rhymes (what English teachers call "the rhyme scheme") is pretty simple in this poem, and Noyes doesn't mess with it at all. We'll show you how it works by looking at the first stanza. We'll put the rhyming words in bold, and assign a letter to each different rhyming sound:
The wind was a torrent of darkness among the gusty trees, A
The moon was a ghostly galleon tossed upon cloudy seas, A
The road was a ribbon of moonlight over the purple moor, B
And the highwayman came riding-- C
The highwayman came riding, up to the old inn-door. B
Pretty easy, huh? Just three pairs of rhymes in each stanza. Check out a different stanza, and you'll see that same pattern (AABCCB) repeating itself over and over.
How about the rhythm of the poem? That's a little more complicated, although once again Noyes isn't the kind of poet who goes too crazy with his style. In general, there are six feet in every line. Feet are the building bocks of poetic meter – see the examples down below. This pattern is called "hexameter" (that "hex-" just means six, like in hexagon).
Now things get more complicated because not all of those beats (feet) are the same. Some have two syllables, and some have three. We'll give you an example from the first two lines. Here the bold text shows where the stress (that means the emphasis) should go, and the feet are divided by slash marks.
The wind | was a tor|rent of dark|ness among | the gus|ty trees,
The moon | was a ghost|ly gall|eon tossed | upon cloud|y seas,
See how that works? Some of those groups between the slashes (those are the feet) are longer and some are shorter, but each one has just one stressed syllable, and both lines have only six feet total.
Before we leave this behind, we should tell you that the short, two syllable feet are called iambs, and they have an unstressed syllable followed by a stressed syllable, like "The wind" (da DUM). The longer, three syllable beats are called anapests. That's a weird word, we know, but it just means that there are two unstressed syllables followed by a stressed syllable, like in line 2: "was a ghost" (da da DUM).
We don't mean to stress you out with all these technical terms – it's just a handy way of talking about how a poem is put together. Don't sweat the details; just keep an eye and an ear out for the rhythm, which is like the beating heart of this poem.