Late on a winter night, Aretha Franklin sat in the dressing room of Caesars Windsor Hotel and Casino, in Ontario. She did not wear the expression of someone who has just brought boundless joy to a few thousand souls.

“What was with the sound?” she said, in a tone somewhere between perplexity and irritation. Feedback had pierced a verse of “My Funny Valentine,” and before she sat down at the piano to play “Inseparable,” a tribute to the late Natalie Cole, she narrowed her gaze and called on a “Mr. Lowery” to fix the levels once and for all. Miss Franklin, as nearly everyone in her circle tends to call her, was distinctly, if politely, displeased. “For a time up there, I just couldn’t hear myself right,” she said.

On the counter in front of her, next to her makeup mirror and hairbrush, were small stacks of hundred-dollar bills. She collects on the spot or she does not sing. The cash goes into her handbag and the handbag either stays with her security team or goes out onstage and resides, within eyeshot, on the piano. “It’s the era she grew up in—she saw so many people, like Ray Charles and B. B. King, get ripped off,” a close friend, the television host and author Tavis Smiley, told me. “There is the sense in her very often that people are out to harm you. And she won’t have it. You are not going to disrespect her.”

Franklin has won eighteen Grammy awards, sold tens of millions of records, and is generally acknowledged to be the greatest singer in the history of postwar popular music. James Brown, Sam Cooke, Etta James, Otis Redding, Ray Charles: even they cannot match her power, her range from gospel to jazz, R. & B., and pop. At the 1998 Grammys, Luciano Pavarotti called in sick with a sore throat and Aretha, with twenty minutes’ notice, sang “Nessun dorma” for him. What distinguishes her is not merely the breadth of her catalogue or the cataract force of her vocal instrument; it’s her musical intelligence, her way of singing behind the beat, of spraying a wash of notes over a single word or syllable, of constructing, moment by moment, the emotional power of a three-minute song. “Respect” is as precise an artifact as a Ming vase.

“There are certain women singers who possess, beyond all the boundaries of our admiration for their art, an uncanny power to evoke our love,” Ralph Ellison wrote in a 1958 essay on Mahalia Jackson. “Indeed, we feel that if the idea of aristocracy is more than mere class conceit, then these surely are our natural queens.” In 1967, at the Regal Theatre, in Chicago, the d.j. Pervis Spann presided over a coronation in which he placed a crown on Franklin’s head and pronounced her the Queen of Soul.

The Queen does not rehearse the band—not for a casino gig in Windsor, Ontario. She leaves it to her longtime musical director, a seventy-nine-year-old former child actor and doo-wop singer named H. B. Barnum, to assemble her usual rhythm section and backup singers and pair them with some local union horn and string players, and run them through a three-hour scan of anything Franklin might choose to sing: the hits from the late sixties and early seventies—“Chain of Fools,” “Spirit in the Dark,” “Think”—along with more recent recordings. Sometimes, Franklin will switch things up and pull out a jazz tune—“Cherokee” or “Skylark”—but that is rare. Her greatest concern is husbanding her voice and her energies. When she wears a fur coat onstage, it’s partly to keep warm and prevent her voice from closing up. But it’s also because that’s what the old I’ve-earned-it-now-I’m-gonna-wear-it gospel stars often did: they wore the mink. Midway through her set, she makes what she calls a “false exit,” and slips backstage and lets the band noodle while she rests. “It’s a fifteen-round fight, and so she paces herself,” Barnum says. “Aretha is not thirty years old.” She is seventy-four.

Franklin doesn’t get around much anymore. For the past thirty-four years, she has refused to fly, which means that she hasn’t been able to perform in favorite haunts from the late sixties, like the Olympia, in Paris, or the Concertgebouw, in Amsterdam. When she does travel, it’s by bus. Not a Greyhound, exactly, but, still, it’s exhausting. A trip not long ago from her house, outside Detroit, to Los Angeles proved too much to contemplate again. “That one just wore me out,” she said. “It’s a nice bus, but it took days!” She has attended anxious-flyer classes and said that she’s determined to get on a plane again soon. “I’m thinking about making the flight from Detroit to Chicago,” she said. “Baby steps.”

Even if the concert in Windsor was a shadow of her stage work a generation ago, there were intermittent moments of sublimity. Naturally, she has lost range and stamina, but she is miles better than Sinatra at a similar age. And she has survived longer than nearly any contemporary. In Windsor, she lagged for a while and then ripped up the B. B. King twelve-bar blues “Sweet Sixteen.” Performing “Chain of Fools,” a replica of the Reverend Elijah Fair’s gospel tune “Pains of Life,” she managed to make it just as greasy as when she recorded it, in 1968.

Before the show, I was talking with people in the aisles. More than a few said they hadn’t seen Franklin or paid much attention to her recordings for years. It was an older crowd, but they hadn’t come to see an oldies show. What reawakened them, they said, was precisely what had reawakened me: a video, gone viral, of Franklin singing “(You Make Me Feel Like) A Natural Woman” at last December’s Kennedy Center Honors. Watch it if you haven’t: in under five minutes, your life will improve by a minimum of forty-seven per cent.

Aretha comes out onstage looking like the fanciest church lady in Christendom: fierce red lipstick, floor-length mink, a brocaded pink-and-gold dress that Bessie Smith would have worn if she’d sold tens of millions of records. Aretha sits down at the piano. She adjusts the mike. Then she proceeds to punch out a series of gospel chords in 12/8 time, and, if you have an ounce of sap left in you, you are overcome. A huge orchestra wells up beneath her, and four crack backup singers sliver their perfectly timed accents (“Ah-hoo!”) in front of her lines. Aretha is singing with a power that rivals her own self of three or four decades ago.

Up in the first tier, sitting next to the Obamas, Carole King is about to fall over the rail. She is an honoree, and wrote “A Natural Woman” with her first husband, Gerry Goffin. From the moment Franklin starts the first verse—“Looking out on the morning rain, / I used to feel . . . so uninspired”—King is rolling her eyes back in her head and waving on the music as if in a kind of ecstatic possession. She soon spots Obama wiping a tear from his cheek. (“The cool cat wept!” King told me later. “I loved that.”)

King hadn’t seen Franklin in a long time, and when she had Franklin was not performing at this level of intensity. “Seeing her sit down to play the piano put me rungs higher on the levels of joy,” King says. And when Franklin gets up from the piano bench to finish off the song—“That’s a piece of theatre, and she’s a diva in the best sense, so, of course, she had to do that at the perfect moment”—the joy deepens.