Up until then, she was just another starry-eyed wannabe, already married with two babies, an ex-beauty queen, stuck on a council estate, with little hope of fulfilling any dreams for a better life. Her mother had a sad history of alcoholism and drug abuse since losing her husband, Lynne's father, from cancer.
It was a Jekyll and Hyde childhood of oppressive cosseting one minute, covert sexual abuse (by her paternal grandfather) the next. Small wonder she bolted at 17, marrying the butcher's boy, also 17.
That fateful audition, prompted by debt, fuelled by brandy, consisted of two songs, ''Puppet on a String'' and ''Summertime'', intended to demonstrate her versatility. Her voice was trembling so much, Marti Caine later recalled, that she sounded like Edith Piaf with Parkinson's disease.
Professionally she wasn't Marti Caine then, or even Lynne Stringer. She was Sunny Smith for all of three weeks, followed by a spell as Zoe Bond. Unhappy with both, she scoured a gardening book for inspiration. Her husband Malcolm Stringer tinkered with tomato cane and came up with Marta Cane. The club she was playing misheard and billed her as Marti Caine.
Singing, she soon realised, came a lot less naturally to her than being funny. Glamorous young women in figure-hugging mini-dresses did not do stand-up comedy in working men's clubs in the 1960s and Caine's novelty value served her well. She walked a tightrope between challenging the male ego, not always the easiest option amid a sea of beer-swilling chauvinists, and affirming preconceptions. She developed a talent for dispatching hecklers with withering one-liners.
By the 1970s she had acquired an agent, John Peller, who persuaded her in 1974 to enter ITV's talent show New Faces. To her astonishment, she emerged the winner a year later, beating Lenny Henry and Victoria Wood.
There followed 10 years of high-profile, top-rating television stardom, international cabaret work and the title role in Fanny Brice in Funny Girl at the Crucible, Sheffield, her hometown. She described the director, Clare Venables, as her Svengali. In partnership with her former agent John Peller and the entrepreneur Sharon Somerset, she also established five health clubs in the north of England. They were her insurance policy if show business ever gave her up.
Her second marriage, to the theatre director Kenneth Ives in 1984, took her into classier realms. A friend of his, the agent Laurence Evans, who succeeded Peller, put Caine in the same brick-dropping league as another client of his, Sir John Gielgud. Famous among these party faux pas was Caine's asking Peter Hall what he did for a living, and on being introduced to a frail yet feisty old man, inquiring of him "Larry who?" only to be told, rather sharply, "Olivier, dear".
The years of popular acclaim and serious money were not enough to eradicate her inner doubt and insecurity. Like anyone who re-invents themselves, she had no way of escaping the person she once was. She still saw herself as an ugly girl with long legs and a nose job. Marti was loud, brassy and egotistical, she told one journalist, while Lynne had no ego and enjoyed doing the housework.
Professionally her aim was always to look drop-dead glamorous whatever discomfort she might have to suffer in the process. She counted dressmakers, hairdressers and beauticians among her closest friends.
Nothing became Marti Caine's life like the leaving of it. Notice was served as long ago as 1988 that her days were numbered. The long and painful fight for survival was charted eagerly by the tabloids, Caine seldom refusing an interview and, when interviewed, never ducking a question.
A book she wrote in 1990, A Coward's Chronicles, was a revelation, inter- weaving poignant snatches of autobiography with a sometimes tortuous, sometimes hilarious account of her treatment. Not everyone under sentence of death wants to know every medical detail. Caine demanded the truth at every turn. By knowing everything, she said, she felt better fitted to use her mind to influence her body.
That she had written so honest and accomplished a book possibly came as no surprise to Marti Caine's intimates, but it revealed a hitherto unseen facet to the viewing masses. For once the publisher's blurb was true: hers was indeed a rare talent. She called it A Coward's Chronicles to counteract the tabloid image of her as this paragon of courage and defiance. You fight for dear life, she said, because you are too cowardly to embrace death. She maintained a punishing work schedule up to a few weeks ago when a relapse forced her to pull out of a Christmas pantomime commitment in Basingstoke, playing the Red Queen in Snow White.
Only her nearest and dearest know how Lynne coped with it all, but the people's view of Marti Caine's last exit was that she conducted herself with dignity, humility and good humour. A coward she wasn't.
Lynne Denise Shepherd (Marti Caine), entertainer: born Sheffield 26 January 1945; married 1962 Malcolm Stringer (two sons; marriage dissolved 1979); 1984 Kenneth Ives; died Henley-on-Thames 4 November 1995.