"No matter how bright I glitter, baby, I could never be gold,” sings Harris on the unrequited-love ballad Gold, one of her own songs on her 21st studio album, All I Intended to Be. While her fans will rightfully consider her to be priceless, it is a fair assessment of her career: Harris is not about musical bling or showbiz flash, just the softly burnished magic of a voice rich in experience and empathy. Let other performers fight for the title of king or queen of their genre - Harris is a folk heroine who choses the simple wooden box over the ornate jewelled one and is rewarded with untold riches for her humility. Her voice might be one of the best-travelled in music (a companion to everyone from Gram Parsons to Bob Dylan), yet 40 years into her career it retains a heartbreaking simplicity that cuts straight to the emotions.

This purity is a theme explored in Tracey Chapman's All That You Have is Your Soul, interpreted here with Harris's effortless clarity: “Don't be tempted by the shiny apple/ Don't you eat of bitter fruit/ Hunger only for a world of truth.” Each song on this record, which is produced by her ex-husband and long-term collaborator Brian Ahern, sticks to this mission statement. Billy Joe Shaver's Old Five and Dimers Like Me - a song that Harris says she felt able to record now that she has past 60 - is kept the right side of sentimental in a touching duet with John Starling, while Broken Man's Lament allows her to cross gender lines and sing of a lost wife and family before the final redemptive surge of instruments.

There are guest stars. The Canadian folk singers Kate and Anna McGarrigle lend their homespun resonance to How She Could Sing the Wildwood Flower and Sailing Round the Room, while Dolly Parton, Vince Gill and Buddy Miller also provide their vocal talents. Yet while Harris never overpowers her songs, this record is fixed by the magnetic north of her voice. If all that you have is your soul, on this evidence Harris is rich beyond measure.

(Nonesuch, TMS £11.99, call 0845 6026328)

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