Pity the poor showbiz kids, with their fractured families and fragile egos, as they try to handle more baggage than an airport carousel.

The Wainwright clan – siblings Martha and Rufus, father Loudon and their late mother Kate – don’t merely air their dirty laundry, they make a public exhibition of it. When it works, the private drama is transformed into universal art; when it doesn’t, it feels like watching a row in a supermarket set to music.

In a curiously nervy performance at the Komedia, Martha Wainwright hit bum notes, forgot the words to her own songs and rambled, occasionally incoherently, between songs. Not that her audience minded. This was less a gig than a gestalt therapy session as the singer bared her soul delivering, as she said, “Sad songs about being out of love and sad songs about being in love”.

Her voice is superb – she possesses a melismatic talent to match Beyonce, Whitney and Christina. The material from her new album, Come Home To Mama, brought out the strongest performances of the night. Highlights included One Black Sheep, Can You Believe It? and a mesmerising version of her mother’s song Proserpina.

Sometimes the family legacy is worth hanging on to.