As fear and insecurity crowd in on the world, that wracking anxiety so often at the heart of the blues has found its moment once again, and Maggie Bell's voice confirms it. More than 35 years have passed since Bell roared into action with her original band, Stone The Crows. At that time she was widely described as Britain's Janis Joplin, a reference to the late American singer whose supercharged vocals often reflected a turbulent life.

Joplin died in 1970 from an overdose, aged 27. Today Bell, who has never courted the bluesy curse of drugs, is still going strong, aged 63. And despite a 20-year absence from the gig circuit, she is still regarded by many as our leading exponent of blues rock.

According to critics, the passion with which she infuses the genre possesses that other quality which has always distinguished true masters of the blues: the raw, authentic sound of suffering.

So, with a global recession threatening to turn lives upside down, does Bell think her kind of music will become the leitmotif of our times?

"Well, the blues, and jazz generally, have never really gone away," she says. But she adds that it was from the 1929 Depression onwards through the 1930s that the music was at its height. People recognised in it something of their own troubles. "But they also found it a kind of therapy, and, I guess, it could be the same today."

Bell returned to the live music scene almost four years ago, having lived in Holland for two decades. But during that time, her voice didn't disappear from the nation's ear. It could be heard extolling her native Glasgow in No Mean City, the theme song for the long-running television series, Taggart. Her back catalogue also appeared on CDs under licence, but without her agreement. Now, having taken control of her old recordings, she is in the satisfying position of selling more copies over the internet than she ever did on vinyl.

Today Bell fills her diary with dates for both home and abroad appearances with different bands, one of which, the British Blues Quintet she founded with old friends, some of whom date from the sixties and seventies. Just now she is in the middle of a two-month tour with Paul Jones and the Manfreds with gigs scheduled for Glasgow's Royal Concert Hall on October 30, and Caird Hall, Dundee, the following night.

And a few weeks ago she teamed up with guitarist Dave Kelly for an event in Dundee as part of Maggie's Dundee's fifth birthday celebrations, sponsored by the construction company Mansell.

"That was the first time I'd been involved in anything for them, but I think they asked me because my name is Maggie and I'm Scottish. They put the two together and thought it would be a nice thing to do. In fact, the occasion turned into a lovely, lovely night."

In conversation, Bell's voice has that potent throatiness so characteristic of the nightclub singer whose most meaningful existence takes place in the dark. But 20 years is a long time without a live audience so, when she stepped back into that unsteady, thrilling territory of the entertainer, was there any stage fright?

"Stage fright? No, never ever because I'm confident in what I do, and I know I do it well."

Suddenly it seems silly even to have posed the question, for this is the Maggie Bell who used to tour with Roxy Music, David Bowie and Marc Bolan; the Maggie Bell of seminal albums, Queen of the Night (1973) and Suicide Sal (1975), each produced by her mentor, the late Jerry Wexler; the girl from Maryhill who toured America's Deep South with Earth Wind and Fire when the group were at the top of their fame.

On that occasion Bell had to open the show but initially audiences seemed indifferent to say the least. So, she hit on the idea of singing her first number from behind a wooden screen, then moved on stage to test the response. "It was phenomenal. You see, by then, they'd liked what they'd heard, despite that early resistance to a white woman from Scotland singing the blues."

As a teenager Bell sang with local dance bands in Glasgow, and in the mid-1960s she went to Germany to sing at US air force bases. On returning to Scotland, she and her partner, guitarist, Leslie Harvey formed a group called Power which later became Stone The Crows. But tragedy struck in 1972 when, in a freak accident, Harvey was fatally electrocuted on stage. With fellow Scots guitarist, Jimmy McCulloch (later with Wings), and drummer, Colin Allen (later with Focus), the band continued for a few months. "But really when Leslie died, the heart went out of the group, and it was never the same again." Stone The Crows broke up the following year, and for Bell, a new era began as a solo singer.

She returned to London from Holland in 2005, after her 20-year-long relationship with "a very sweet man" had ended. "When we'd first met, I'd never really taken time off and I thought that perhaps this was the moment to settle down and have a normal life." Bell is reluctant now to talk much about those years. But eventually tension arose because her ex-partner, who was in computers, didn't want her to pursue her career.

"I'd find myself thinking: I could be doing gigs. I'm a singer. I don't have children, so I could go back to work while I've still got a voice."

What kept her going through the loneliness of those years was her dog, Oran, named after the street in Maryhill where both her parents were born. He was the love of her life, she says, and she'd walk him for four hours a day, trying to puzzle out what, for her at least, was a normal life.

Eventually the lure of the blues won. At the invitation of keyboard virtuoso Zoot Money, Bell came to London, and with Scots guitarist Miller Anderson, bass guitarist, Colin Hodgkinson, and drummer, Colin Allen, the British Blues Qunitet was born.

"We're more like a family than a band." But where is home now? "Well, like lots of my friends who are musicians, I'm a bit of a gypsy. Life's a journey, and home is wherever it takes you."

As for life on the road, Bell says it's just like it always was, except that she is enjoying it more than she did 40 years ago. "No pressure from managers or record companies telling you what to do. No worries about fame or whether you'll get into the charts. All that stuff stresses you out when you're young.

"I'm my own boss now and the bonus for me is that I'm still alive and singing." Not a bad bonus for us, either, Maggie Bell.

Maggie Bell is at Glasgow's Royal Concert Hall on October 30 and the Caird Hall, Dundee, on October 31.