During Betty Buckley’s rendition of Joni Mitchell’s “Both Sides Now” last Saturday at Joe’s Pub, I had a succinct thought about the legendary singer: She makes you feel your heart is full.

Among other glowing adjectives, her shows have been called “magical,” but what she does is not magic. It is instead so rooted in her being that she need only allow the branches to spin out and encircle her listeners. As she told me last fall when I interviewed her for VanityFair.com, Betty is a longtime practitioner of meditation, crediting it with giving her the means not only to navigate the extremes of Hollywood (one of her closest friends was John Belushi) but also to find both the focus and the abandon—informed abandon—that caused her career to take off.

Her choice of songs in this show, called “Dark Blue-Eyed Blues,” reflected both a playful personality (“Them There Eyes,” sung at warp speed by, as she said, a slow-talking Texan; “I Get a Kick out of You,” directed at a lucky audience member having a birthday) and a deep soul (“This Nearly Was Mine,” an elegant cri de coeur from South Pacific; “All the Pretty Horses,” in which she unearthed the sadness—what baby will ever have “all the pretty little horses”?—beneath the lullaby).

Other standout songs included the achingly beautiful “Too Many Memories” by her old friend the guitarist Stephen Bruton, who died in 2009. Introducing it, she revealed that she will be receiving the award named for Bruton at this year’s Lone Star Film Festival; it’s given to a musician who has also contributed to film (as Bruton did, helping to score Crazy Heart). I first became aware of Betty through a film—Tender Mercies, in which her tormented-country-star character tore the guts out of the song “Over You.”

During her set, Betty also brought out the pathos in Sting’s Last Ship song “Practical Arrangement,” the longing in the Leonard Cohen classic “Bird on the Wire” (holding on to that last word, “free”), and, invoking her “guardian angel” Elaine Stritch, the triumph of Stephen Sondheim’s “I’m Still Here,” belting out those final resounding “here”s in a grinning, gritty, Stritchian way.

Last week the Bay Street Theater in Sag Harbor, Long Island, announced that Betty will be playing Big Edie to Rachel York’s Little Edie in Grey Gardens there in August. With the transcendent force that is Betty Buckley, any grey gardens in that musical are likely to suddenly burst into bloom.