Martha Wainwright has a big personality. Like her brother, Rufus, she composes folk-based pop tunes with rich melodies, but where he prefers elegance, she seems constantly on the verge of a primal scream. Wainwright’s nervous, slightly raspy voice adds simmering tension on the sweetly melancholy “Far Away,” which could be a Carpenters song gone wrong. She plunges headlong into anger in “Ball and Chain,” a stormy tale of predatory sexuality, crying, “Why does this always happen?” then turns to self-loathing, exclaiming, “I will not say I’m all right for you,” accompanied by stark acoustic guitar on “B.M.F.A.” (a.k.a. “Bloody Mother Fucking Asshole”). Such confessional angst is never depressing, however: Wainwright’s willingness to embrace emotional extremes produces thrilling music that’s utterly cathartic.