Having made a minor but respectable name through her shrill, sometimes earsplitting wailing—and, more notably, by transforming the epithet "Bloody Motherfucking Asshole" into one of the most strident, heart-wrenching kiss-offs ever administered—alt-rock heroine Martha Wainwright is taking her final steps out from under big brother Rufus' well-groomed shadow.

Though a clean collection of bittersweet folk-rock mini-arias, it is nonetheless hard to ignore her latest album's most obvious hurdle: surpassing the nearly unattainable benchmark set by her sterling self-titled debut from 2005. Forgetting for a minute her supporting vocals recently on a tepid Snow Patrol ballad, Wainwright seems to have been training for the challenge. And I Know You're Married, But I've Got Feelings Too (June 10, Zoe/Rounder Records) is proof.

By bringing aboard talent like Pete Townshend, Steely Dan's Donald Fagen, and mom Kate McGarrigle and Rufus, Martha explores more experimental terrain. Frequently, and thankfully, the flourishes are merely fluff. And though the poignant brother-sister duet "The George Song" is a clear stand-out, she's even stronger on tracks like "Bleeding All Over You" and "Hearts Club Band," where Wainwright delivers with delicately restrained angst—a trait that Alanis Morissette would be wise to pick up on between lofty concept albums.

Married's weakest link lies in its sometimes overcooked production. Unlike the rougher edges of her debut, this one is a tidy conflation of dolled up folk and cabaret-style theatrics. This fault, however, is a nitpick at best. Ultimately, the album is one of the best of the year so far. And if Married doesn't quite reach the incredible heights of her debut, it may well be because that feat was never possible.