Rufus & Martha Wainwright in Tribute to Their Mother

"It's the closet thing that I can get to a religious acceptance of death," Martha Wainwright explains, while calling on the phone from her hotel room in Adelaide, Australia. The singer-songwriter's referring to the solace that music can bring to the unwell or grieving. Martha and her brother, Rufus Wainwright, have been seeking comfort in music since the passing of their mother, folk singer Kate McGarrigle. The pair has been performing tribute concerts across the globe and this week, with a show on June 26 titled "Kate's Kids" at the Brooklyn Academy of Music, will be the penultimate one.

McGarrigle died of Sarcoma, a rare form of cancer, in 2010. During the last years of her life, she set up the Kate McGarrigle Fund in the hopes that one day there would be a cure. The fund would later become the Kate McGarrigle Foundation, of which Martha and Rufus are the heads. Admittedly, the fund is modest when compared to other cancer foundations. "What we do is, we don't raise huge amounts of money, we raise money with these shows and we enlist the help of young doctors, who are in research and trying to find cures for sarcoma," Martha explains. All of the proceeds from the concert will benefit the Kate McGarrigle Foundation.

Included in the ticket price is a copy of Sing Me The Songs, a double album made up of live recordings from the past tribute concerts in London, New York, and Toronto. These concerts themselves are, in a way, fulfilling one of McGarrigle's life-long wishes: that her children play music together. "She was pretty vocal for several years that we should have been a duo," Rufus says. "In a certain respect, I think she might have been right, we sound nice when we sing together. Nick Hornby, in an essay he wrote, once called Matha and me singing together 'the sound of God' and our mother never stopped bringing that up."

Some of their friends and collaborators--including Norah Jones, Emmylou Harris, Mark Ronson, Jane McGarrigle, and Lily Lanken--will accompany Martha and Rufus in singing a mix of their own songs, some of their mother's, along with songs that were inspired by Kate McGarrigle. (Watch a clip from the film of a group singing, "Proserpina," the last song Kate McGarrigle wrote before she died.)

While one of the goals of the tribute concerts is to raise money for the foundation, there's another more personal purpose behind these shows: closure and to further their mother's legacy. "It's a way to comprehend and accept death," Martha says. "But It's also a way to stay connected to her. There's never full closure and I don't really want there to be." Rufus agrees, adding that it's very "forward-thinking. I think whereas the concerts in the past were really dwelling on the mourning process and the loss of a genius, this one is more about her legacy and looking toward the future and to translate her influence in the future."

Kate's Kids will take place at BAM on June 26. A screening of the documentary, Sing Me the Songs that Say I Love You, takes place June 25 at BAM, June 26 at Film Forum.