First ladies of folk Kate and Anna McGarrigle have been singing and playing together since they were children.

The French-Canadian sisters' decades of familiarity showed clearly in their faultless musical blending and relaxed onstage banter.

Their tendency to go off on extended conversational tangents when explaining the origins of songs was both endearing and enlightening, like watching a pair of your favourite aunties reminisce at Christmas after the second bottle of red.

If, that is, your aunties happen to be experienced musicians who can reel off traditional feet-stamping gospel as convincingly as their own modern folk.

The McGarrigles and their equally talented band dug through a consistently winning hope-chest of tunes from their latest French album to their first attempts at song-writing.

This rummage through the treasure-trove demonstrated the richness of their musical knowledge and lyrical ability - there were threads of folk traditions and harmonies from Appalachia to the Bahamas.

They gave the lyrics of William Blake's poem Ah, Sunflower a lilting, string-heavy setting which was pure San Francisco hippie; belted out a full-throated, spine-tingling rendition of gospel song Dig My Grave and mixed in adult sadness to a poignant New Orleans children's skipping song.

Kate's song about her old lover, now a teacher, mistaking her daughter Martha for herself was a particularly lovely meditation on age, youth and might-have-beens.

This pair of old pros can make an evening of top-quality music-making feel like a family party: A rare gift worth paying for.