Howl sounds like a mix between a Zen-like chant and (quoting a line from Walt Whitman) a "barbaric yawp." Although it has no regular meter, the poem repeats the same words and phrases over and over, like an Eastern sage repeating a mantra. "Who…who…who." "Moloch!…Moloch!...Moloch." "I'm with you…I'm with you…I'm with you." In recordings of his readings of the poem (listen to Ginsberg read Howl), Ginsberg speaks in a slow, mesmerizing, almost robotic monotone, in contrast to the yelling and shouting you might expect from the title.
Howl is a difficult poem to read aloud, mostly because you get to take so few breaths. Ginsberg has said that each line should be spoken in one breath (source), but try saying line 71 in one breath: not so easy, is it? You have to have the lungs of a professional trumpet player to get through a "performance" of Howl. The Beats took their cues from the late-night impromptu jazz marathons they often witnessed in Denver, New York, and Chicago.
In terms of content, Howl is totally over-the-top, with extensive uses of slang, a boatload of proper names, mountains of thick description, and lots of words that end with "–ing".
Line 5 is pretty typical. The line starts with alliteration and a rhythm straight out of bebop jazz: "who bared their brains to Heaven under the El." Ba-dum, ba-dum, ba-dum, badaba-dum. Then he throws in "Mohammedan," which is an archaic word for "Islam" because it sounds cool and adds a new variation to the beat: badaba-dum. In other words, Ginsberg writes poetry for a full, seven-piece drum set. Then, rather than use a simple word like "walked" or "paced," he puts in a show-stopper: "staggered." If there's an opportunity to pump more drama and emotion in his verse, you can bet Ginsberg's going to pounce on it like a dog on a chew-toy. Then he rounds off the line with a final rhythmic variation: "illuminated," which has the same accented second syllable as "Mohammedan." And that's just one line out of 112. Don't tell us free verse isn't complicated.
One last point, which we've made elsewhere, is that this poem sounds like someone talking very fast and who may have strayed from his sanity. When he says, "who poverty and tatters" in line 4, we know he actually means something like "who live in poverty and wear tattered clothing." But Ginsberg doesn't want to use that many words. Plus, he wants to give an idea of how exhausted and unbalanced these people are. He seems to use the first words that pop into his head, which creates a sense of spontaneity. Moment by moment, line by line, there's always something interesting going on in the sound of Howl.