A singer of beguiling charm and disarming vulnerability

Kate McGarrigle was a singer and songwriter whose gentle sensibility was an endearing feature of contemporary folk music for more than three decades. Her partnership with her younger sister, Anna McGarrigle, was notable for melancholy songs and tender harmonies.

Recently, Kate McGarrigle's fame has been burnished as Rufus and Martha Wainwright - her children with the singer Loudon Wainwright III - became major stars for a new generation. Last December, McGarrigle - looking frail but otherwise in good form - played with Rufus, Martha and various other family members and friends at a cancer charity concert in London.

Kate McGarrigle ... a proud mother.Credit: Domino Postiglione

Kate McGarrigle was born in Quebec on February 6, 1946. Her father, Frank McGarrigle, was an Irish pianist, and her mother, Gabrielle, a French Canadian classical violinist. Kate and her sisters, Anna and Jane, were raised in the village of Saint-Sauveur.

She was taught piano by local nuns and by the time she left home to study engineering at university in Montreal, she was also playing banjo, guitar, accordion and various other instruments. Anna was also in Montreal, studying art, and they started singing together on the lively Montreal folk circuit.

But it was only after moving to New York and making her mark on the Greenwich Village folk scene that her songwriting blossomed and her career began in earnest. It was also there that she met and embarked on a tempestuous relationship with Loudon Wainwright III, the subject of some of her most emotional songs. They married in 1971.

Warner Brothers offered Kate and Anna a record deal as a duo. Their debut album, Kate & Anna McGarrigle, was fraught with problems as producers disagreed over whether they should be tailored as a folk or pop act but, full of beguiling charm and disarming vulnerability, it was eventually released in 1975 to ecstatic reviews.

Subsequent albums Dancer With Bruised Knees (1976) and Pronto Monto (1978) followed a similarly whimsical style without matching its success and, with two small children and a bitter break-up with Wainwright to contend with, McGarrigle happily avoided the limelight. When the sisters did play live, fans loved their unconventional, unsophisticated honesty, which they regarded as a welcome antidote to the big production onslaughts favoured by most rock bands at the time.

They were dropped by Warner Brothers and, in what they originally regarded as self-indulgence, collaborated with the Canadian poet Philippe Tatartcheff on the 1980 album Entre la Jeunesse et la Sagesse. Sung entirely in French, it made no commercial sense at all, yet its rootsy feel and rich harmonies proved a hit with even non-French speaking audiences.

The later emergence of her children inevitably attracted more interest in the growing musical dynasty. There was even a reunion of sorts with Wainwright III when he joined her on The McGarrigle Hour (1998), a family record concept that was revived in 2005 with The McGarrigle Christmas Hour.

McGarrigle took great pride in the success of both Rufus and Martha, regularly joining them both on stage.

McGarrigle was diagnosed with clear cell sarcoma in 2007 and founded the Kate McGarrigle Fund cancer charity in 2008. She remained warm, funny and resolute to the end.

She is survived by her former husband and their children.

Telegraph, London