Martha and Kate and Edith Piaf

You could learn a lot about a singer by the way he or she steps on stage. Lady Gaga’s entrances guarantee an epic costume, Madonna’s an onslaught of HD video, Mariah Carey’s at least one giant fan blowing.

Yet at a Martha Wainwright concert, the star of the show seldom makes a splash when the curtains open. “It’s her magic trick,” says avid fan, actor-model Isabella Rossellini, who has seen Wainwright sing live several times. “Martha walks into her set very modestly, very subtly,” Rossellini explains. “At first, you might think that she could be part of the band. Then, bang! That strong voice comes out and she traps you in a time machine!”

Rossellini isn’t the only one who believes in Wainwright’s Star Trek-esque ability to alter the time-space continuum. Shortly after the 34-year-old Canadian finished touring her second full-length album of country-tinged pop, I Know You’re Married But I’ve Got Feelings Too, she was approached by producer Hal Willner to record a new live album of Edith Piaf covers called Sans fusils, ni souliers, à Paris. A fan of Wainwright’s whole musical family—including her recently deceased mother Kate McGarrigle, virtuoso older brother Rufus Wainwright and father, Loudon Wainwright III—Willner was confident the Quebec-raised chanteuse could reinvent Piaf’s songs. “I said yes to Hal almost immediately,” Wainwright says via phone from her home in Montreal. “I was six when my mother started singing these tremendously emotional Piaf songs to me,” she recalls, noting she now hums the same tunes to Arcangelo, her seven-month-old son with her husband, drummer-producer Brad Albetta.

Wainwright says the 15 Piaf tracks she chose to revive were “patrolled and approved” by her mother: “It was the last thing we were able to do together before she passed away. It meant so much for me to have her be such a big part of it. Especially because she was adamant that I record her favourite track—C’est toujours la même histoire—she liked its melody and sensibility. She also nixed a few terrible ideas and helped with mixing and mastering the album.”

One piece of advice McGarrigle kept reiterating was that Wainwright simply “trust herself.”

Which is why her daughter decided to stay away from researching Piaf’s trauma-laden life by rereading any biographies. She also banned Marion Cotillard’s Oscar-winning performance in the 2007 Edith Piaf biopic La vie en rose from her DVD player. The result? Some of Wainwright’s best work can be heard in Le chant d’amour and Une enfant, in which she amplifies, downplays, accessorizes and sometimes completely ignores Piaf’s vocal delivery.

Aside from the Piaf project, Wainwright’s pipes have been in demand by high-profile rockers, including Courtney Love, who called on Wainwright to sing supporting vocals for Hole’s comeback album, Nobody’s Daughter.  David Byrne, who recently collaborated with Wainwright on a compilation disc called Here Lies Love, says there is a reason everyone now wants her.

“For years the focus was solely on her brother but it was clear that all eyes were on her after Martha stole the show when she [sang] Stormy Weather during his Judy Garland tribute [in 2006]. It was her big f–k-you to the world [and] an artistic turning point.”

Still, schmoozing with the celebrity pantheon isn’t a high priority for Wainwright these days. She is currently piecing together a piece of theatre written by her mother and aunt. “It’s a musical about Mrs. Chadwick, a female con artist from the last century. The songs are hilarious. I want to play her.”

Also top of mind for Wainwright is headlining a Canadian and European tour (some dates are with her brother), which kicks off on June 20 in Ottawa. “Rufus will be wearing a 17-foot train dress [by Michael Jackson’s costumer Zaldy] and have artwork by Douglas Gordon [a 30-foot-high replica of Rufus’s eye] to accompany him on stage,” she says with a chuckle. “I’m just going to have a pair of pants and a guitar. But don’t worry, I’ll make do.”