Judy Collins has notched up 50 years in music, but, she tells Rob Adams, she�s working as hard as ever and is looking forward to playing Scotland.

Judy Collins doesn't like looking back. Having lived through dark times, which include her own alcoholism and her son, Clark's suicide in 1992, the singer best known on these shores for her trio of hits in the early 1970s - Amazing Grace, Both Sides Now and Send in the Clowns - prefers to dwell in the here and now.

If only she could. Given her profession, the simple act of singing a song will bring back memories. Then there's her writing: having produced memoirs and self-help guides on coping with bereavement, as well as novels, she is working on a book about her 50 years in music.

Collins's most recent journey into the past was actually her own doing. Released last year on her own record label, Born to the Breed, a collection of her songs performed by singers and admirers, including Joan Baez, Leonard Cohen, Dolly Parton and Chrissie Hynde, made the point that not only has she been one of the most consistently compelling interpretative singers of her generation, there's more to Collins than being the singing equivalent of a clothes horse for songwriters. She's a great songwriter herself.

Born to the Breed turns the tables on some of those involved, Jimmy Webb being a case in point. Having recorded Webb's classic The Moon is a Harsh Mistress way back, Collins invited him to sing her Fallow Way on the album. Then there's Leonard Cohen, whose songs Collins championed to the extent that she can take credit for his emergence as a recording artist.

Introduced by Collins's friend Mary Martin, Collins and Cohen met when the Canadian poet and novelist turned up on her doorstep in Manhattan one afternoon in 1966. "Mary was from Canada, too, and knew I was looking for new songs. She told me about this guy she'd met who'd just started to write," says Collins. "But when Leonard walked into my apartment, I didn't care if he wrote songs or not. He was gloriously handsome."

Cohen was also shy and took some persuading to sing to Collins. But when he did, the first two songs he sang - Suzanne and Dress Rehearsal Rag - went straight on to Collins's next album, In My Life. Collins has now recorded upwards of a dozen more Cohen songs, although she was never the lover alluded to in them, as she was when Stephen Stills delivered Suite: Judy Blue Eyes on the first Crosby, Stills & Nash album. She did, however, take up Cohen's suggestion that she write, composing Since You Asked in direct response and finding the process surprisingly easy.

Collins did a similar service for Joni Mitchell, after a then-unsigned Mitchell had sung Both Sides Now down the phone to Collins during a 3am call from singer-songwriter Tom Rush. Her ear for a good song was something Collins inherited from her father, Charles, a singer and pianist who, she says, also passed on his liking for strong drink to his daughter, as well as his love of Irish ballads and show songs. It was as a concert pianist that her parents saw their oldest child initially, however, sending her for lessons in Denver with the piano instructor and conductor Antonia Brico.

Brico inspired Collins to practise piano, too, and the youngster made her concert debut at the age of 13. Brico was preparing her for another recital when Collins broke the news that she'd found another muse, folk song. "I couldn't have continued with classical music," says Collins, "because although I could play them well enough, the pieces I was learning had no lyrics and somewhere inside me there was a singer. I loved story songs from an early age and, as well as my father singing around the house, my grandmother sang to me. That's where I heard Amazing Grace. But, then, I've always thought of what I do as part of the oral tradition."

On an old National guitar, Collins began learning as many folksongs as she could. By the time she was 18, she was ready to join the musical revolution in the US in the 1950s. One night in the Gate of Horn club in Chicago, to where she'd moved, she listened spellbound to Cynthia Gooding. She promised herself that she'd follow in Gooding's footsteps.

She did - right down to her choice of record label - and, in fact, completely outpaced her hero. Collins's arrival in New York, followed by national acclaim, coincided with Dylan's. She remembers drinking whiskey with him in the Greenwich Village venue Gerde's Folk City and his songs played a part in her rise to prominence. But when Collins sought Dylan's permission to use his song Time Passes Slowly in the film The Recidivist, her request was greeted with silence. By this time, however, she'd taken up Cohen's suggestion that she write her own songs and Easy Times, which appears on Born to the Breed sung by bluegrass singer-guitarist Jim Lauderdale, took the Dylan song's place in the soundtrack.

As she grew into one of America's most popular singers of the 1960s and shook off her alcohol addiction, Collins developed business sense. She even picked a fight with the Royal Scots Dragoon Guards - and won - when they adopted her arrangement of Amazing Grace and turned it into a rare international hit for a pipe band. "They used my harmonies, so we made a claim for royalties," she says. "It was a public-domain song but it wasn't a song you heard much before my recording. Now you hear it everywhere, especially played by bagpipers. So in the same way as I made Suzanne famous for Leonard Cohen, I like to think that I brought Amazing Grace back to prominence."

These days, approaching her seventieth birthday, Collins keeps up a busy schedule, playing concerts, running her Wildflower record label, writing, acting and painting. And having realised during the making of Born to the Breed that there are some of her songs that other singers want to record, she's planning Volume Two.

"It's a lovely feeling to know that so many people want to be involved and it's gratifying to think there are enough songs that were missed out first time to make another collection," she says. "When I started, my songwriting was autobiographical, then I started responding to situations and there were songs like the Blizzard, which I began writing because I'd never written about Colorado before, but it turned into something that might have been a movie. In fact, I've spoken to a film-maker about casting it as a movie. Maybe I should approach Clint Eastwood " With her track record and powers of persuasion, I wouldn't bet against Clint helping her to realise her ambition.

Judy Collins plays the City Halls, Glasgow, tonight as part of Celtic Connections.
Sponsored by ScottishPower.