Migos performs at Echostage. (Raquel Zaldivar/For The Washington Post)

To better understand why the mass shout-along at a Migos concert feels so profoundly exultant, don’t listen for the hits. Listen for the consonants. And maybe don’t worry about the vowels.

Rap has long been measured by the artfulness of its rhymed verses, but today’s most significant rap artists seem far more interested in the words themselves — how they launch from the lungs, take shape in the throat, then ricochet out of the mouth and leap into the music. It’s a back-to-basics kind of expressionism, similar to what the punks did to rock-and-roll eons ago, but it should obviously be listened to on its own terms.

That requires turning your ears toward Atlanta, rap’s current epicenter, where rappers are making important decisions about how best to deploy their tongues and their lungs. Migos — the chart-topping trio whose members rhyme in hypnotic staccato blasts — are devoted to consonants. They tend to keep their words short and tight, burning through their vowels, impatient to get to the next plosive. Future and Young Thug work another way, emoting more intensely through their oohs and aahs. They know that there’s space to move around inside those vowel sounds. You can travel from one note to another on a vowel. You can tell a story with a vowel. You can use vowels to communicate the rawest feelings. You can use them to tell lies, too.

Consonants are far less flexible, so it’s easy to hear them as the truth — and rap music has always been obsessed with truth, or at least the idea of it. “Recognize a real don when you see one,” the Notorious B.I.G. rhymed in the final year of his life, proving he was the best consonant-minded rapper who ever walked this earth — his words always sounded absurdly luxurious as they bounced and squished their way across his palate. And it’s telling that one of Biggie’s better emulators, Rick Ross, didn’t have to forfeit his image as a drug kingpin when it was revealed in 2008 that he had previously been employed as a corrections officer. Ross was a fake, but his consonants sounded entirely real.

Migos peddle similar narco-fantasies in their hit singles, but it’s their consonants that give the music its crackling energy. The same principle applies to any big rap concert. It’s an opportunity to hear a massive crowd crash-land on those consonants all together. And that’s an entirely different thing than, say, whoa-whoa-whoa-ing along to the White Stripes’ “Seven Nation Army” at some sporting event. Everyone is welcome inside a “whoa,” but at the rap show, the right to participate must be earned. You need to know where the consonants fall.

During Migos’s headlining set at Washington’s Echostage on Sunday night, (technically Monday morning), this idea first made itself apparent during the woozy thunder of “Slippery,” a song where the word “splash” appears twice in the refrain. Each time the trio — Quavo, Offset and Takeoff — arrived at the “shh” at the end of that word, they were joined by hundreds in the audience, everyone pushing hot air through their teeth. “Shhh” is the sound we use to quiet one another, but here it was louder than the rumbling of the club’s massive sound system.

Over the shy piano twinkles of “Call Casting,” it was Takeoff’s turn to cast aspell: “Trap turned Zaxby’s!” He was comparing the efficiency of a drug-dealing operation to that of a fast-food chain, but notice the brands he didn’t cite. It’s not that Popeye’s, Church’s and Nando’s have slower customer service. It’s that “Zaxby’s” has a Z, an X, and a B.

Toward the end of the night, Migos rapped as if they wanted to test the flexibility of their biggest hits — Offset unfurled his verse from “T-Shirt” in riveting a cappella while Quavo enhanced “Bad and Boujee” with a freestyle that zeroed in on Donald Trump. The president’s name was preceded by an F sound, then some other sounds.

The crowd responded with its loudest cheer of the night — all vowels.