"How's your father," shouts one wag in the audience. It must be a familiar question. The Wainwright family overflows with musical talent: Martha's father, Loudon III, was once regarded as the new Dylan, mother Kate McGarrigle is a famous folk musician and brother Rufus's lush pop has sold in bucketloads. Her own fine 2005 debut dealt with her nearest and dearest with acerbic honesty: live, she has introduced its standout track, Bloody Mother Fucking Asshole, with the words "This is a song about my dad".
Tonight, Wainwright is on less confrontational form, describing Rufus's last album as "a triumph". For all her good-humoured charm, though, the music doesn't seem to be getting any more optimistic. She describes her second album, due in 2008, as "morose"; of the promising new songs she plays tonight, one is dedicated to a friend who recently committed suicide and another veers close to fado territory.
Whatever she plays, Wainwright is never less than bewitching. During the uptempo moments - which include a splendid Eurythmics cover - she stabs her killer heels into the ground, her hips flicking joyfully while her band pump out a rollicking backing rhythm. She plays other songs solo, her voice rising to a strident shout and diving to a barely audible yelp: the effect is that of a series of cathartic showstoppers.
Just before the encore, she is joined by Pete Townshend and his partner, Rachel Fuller; it's testament to Wainwright's charisma that when the two do a perfectly decent song without her, the aisles are crowded with audience members turning their back on the Who legend and heading to the bar. But Townsend's presence makes for an awesome finale: Wainwright delivers Bloody Mother Fucking Asshole's lines with trembling, scathing intensity as the guitarist takes his cues from her, underpinning the song's potent charge with bursts of tightly controlled chaos.
