If I say “Wainwright,” you’ll say “Rufus.”

Which is the right first response.

If you had a second response, though, you might name my favorite Wainwright.

Who could, by the time you finish this, be yours as well.

Martha Wainwright has the same parents as her brother—the singer-songwriters Kate McGarrigle and Loudon Wainwright III—but their styles couldn’t be more different. He’s a diva (he has performed a concert of Judy Garland songs) and an opera lover (he’s written one). She’s an introspective songwriter who can, in a phrase, morph from a victim to a champ. Confessional? One of her CDs is “I Know You’re Married But I’ve Got Feelings Too.”

I first encountered Martha on YouTube, in a duet with her brother. The song is the Leonard Cohen classic, “Hallelujah”—a crowd-pleaser whenever Rufus performs it. But watch what happens when it’s Martha’s turn, which begins around 2:20.

Right: Rufus who?

I first saw her onstage at a terrible venue. It was the last benefit of the summer in the Hamptons. Rufus and Norah Jones were the headliners. Martha was the opening act. As she came on stage, the audience was checking its makeup, texting, drinking, chatting.

Talk about your uphill swim! Martha began singing—in French—an Édith Piaf song. The talking continued. She put a hand in the air, lost in the world of France’s most celebrated singer. In another minute, she had the attention of those inattentive Hamptonites. In ten, she pretty much owned them.

She went on to record an all-Piaf CD, “Sans Fusils, Ni Souliers, A Paris,” which is less an imitation of Piaf than a reinvention.

Next up—and why not?—is Janis Joplin.

Cohen, Piaf, Joplin: what’s the through line here? For me, it’s the immediacy of a great artist performing live. So, yeah, Martha Wainwright’s CDs are just fine. But you won’t get the full effect until you see her on stage.

There are, happily, two chances to see her in New York before the ball drops in Times Square.

First up is City Winery, a civilized, intimate room where it’s easy to feel the singer is there just for you. Two chances here: 11/11 and 11/21.

A more expensive ticket is the Town Hall event: “A Not So Silent Night,” on 12/15. The headliners are Rufus & Martha, but if this concert is at all like the one they gave at Carnegie Hall a few years ago, some very distinguished friends and relatives will drop by.

At Carnegie, Rufus was the host and the dominant Wainwright; at one point, he stepped away from the microphone and filled the hall with a thrilling “Ave Maria.” Time changes everything. Rufus hasn’t been standing still, but Martha’s definitely been evolving into much more than his backup singer and duet partner. This time around, Rufus might be first among equals—or, simply, the man who introduced us to his sister.