Bob Dylan performs on stage during the 21st edition of the Vieilles Charrues music festival on July 22, 2012 in Carhaix-Plouguer, France. The 73-year-old music icon brought his Never Ending Tour to Washington’s Constitution Hall on Tuesday night. (Fred Tanneau/AFP/Getty)

Bob Dylan at 73: Still touring, still vexing, still wearing terrific suits.

And so the mysterious oracle of American song stood before a full house at Constitution Hall on Tuesday night, trudging through more than two hours of music that felt enchanting at moments, punishing at others.

Dylan has been out on the road for so long, calling his act a “tour” seems silly. It’s a way of being. Nowadays, the transaction goes something like this: His congregants — tethered to their stations in life — show up each year to bask in the maestro’s tumbleweed wisdom. But to glean it, they have to listen closely, because the man still sings his songs as if he’s being dragged across them. As the years saunter past, Dylan becomes more stoic, more cryptic, less intelligible, more demanding, offering communion completely on his terms. And to quote his first discernible lyric of Tuesday night’s gig: “The human mind can only stand so much.”

But he did seem spry up there. Dylan spent much of the show leaning into the microphone, as if telling it a dirty joke, clutching the lapels of his margarine-colored suit. He’d often finish his gnarled, grunty verses with celebratory flutter-steps across the stage, and then plant his left hand on his hip as he surveyed his flock.

On the menacing “Pay in Blood,” he suddenly looked like an overdressed gangster who’d come to collect his cash. “I’m grinding my life out, steady and sure,” he sang as his band gave the proceedings a mild swagger. “Nothing more wretched than what I must endure.”

That was one of five selections from Dylan’s 19-song set that came from “Tempest,” a 2012 album littered with corpses, junkies and other ugliness evocative of the old American frontier. It stands as Dylan’s most intriguing album since his 1997 comeback, “Time Out of Mind,” but onstage, many of these songs quickly became exhausting.

Like during “Early Roman Kings” when Dylan and his five-man band conjured a roadhouse blues that plodded like a death march. The audience — already relatively frozen in their seats — appeared to reach complete stasis beneath each crack of the snare drum.

But he followed it with the 2009’s “Forgetful Heart,” singing about nostalgic love in relatively long, melodic phrases, proving that his harsh, illegible croak is a purposeful aesthetic choice. As ever, this man’s art is about refusing to do what’s expected of him (even though we’ve grown to expect that).

Another thing Dylan didn’t do on Tuesday: mention the word “Ferguson.”

With protests against police brutality unfolding across the country as Dylan paced the stage, the only non-sung words he had to offer involved thanking the audience before a mid-concert intermission. But that’s no surprise, really. In the banter department, Dylan has been practically mute for years, and he forfeited his responsibilities as a protest singer decades ago.

Still, some may have heard a coded response to the week’s events in his encore of “Blowin’ in the Wind,” an era-defining riddle transposed here into a honeyed slow dance. Each of the song’s nine questions felt soberingly timeless, but one in particular stood out: “How many deaths will it take till he knows that too many people have died?”

That 52-year-old song could have made for a poignant closing statement, but Dylan stuck to the set list he’s used at every gig for the past month. He followed “Blowin’ In the Wind” with “Stay with Me,” a ballad made famous by Frank Sinatra — one last reminder that Dylan's current work is deeply intoxicated by America’s past and seemingly impervious to its present.