Kathy Kirby: Singer best known for 'Secret Love' and her appearance in the Eurovision Song Contest

If steeped in the conventions of traditional British showbusiness, Kathy Kirby thrived as a solo vocalist in an age of beat groups.

Moreover, she remained a source of fascination at odds with her mere handful of chart entries. These were adjuncts to the earnings she had accrued as a stage (and then television) performer since 1956, when she had fronted a ballroom orchestra under the baton of Bert Ambrose, her mentor (and rather elderly boyfriend) until his death in 1971. Then came perhaps the most extraordinary phase of Kirby's career, underscored as it was by a disastrous marriage, bankruptcy and tabloid exposure of a turbulent private life.

Born Kathleen O'Rourke, one of three siblings, in Ilford, Essex, her bel canto soprano and selections from the classics ensured victory in local talent contests. On leaving convent school in 1954 she sang semi-professionally while holding down a day job as a telephonist with the Ilford Recorder newspaper. Her repertoire now embraced music hall favourites as well as items from the newly-established New Musical Express record sales and sheet music charts.

Her local popularity was brought to the attention of Ambrose by her stepfather, who worked in the West London hotel where the famous bandleader was a guest. However, it was her moist-lipped resemblance to Marilyn Monroe – emphasised by dyeing her naturally red hair platinum blonde – as much as other talents that led to the 18-year-old's recruitment by Ambrose, who was impressed by her unscheduled renderings of "Love Me Or Leave Me" from her girlhood idol Doris Day's latest movie, and Johnnie Ray's "All Of Me" with the ensemble one night at Ilford Palais.

On adopting her familiar stage alias, Kirby's stock-in-trade was a certain daredevilry with standards fromas far back as the 1930s, though Ambrose permitted concessions to relatively current pop, instancedby cover versions of Teresa Brewer's 1955 hit "Let Me Go Lover" andDoris Day's 1954 million-seller, "Secret Love". He also allowed his protégée stints with other big bands beforeher headlining cabaret seasons in Madrid and London – notably, six months at Mayfair's Blue Angel club – and, later, on round-Britain package tours with Cliff Richard and Duane Eddy after her television debut on ITV's Cool For Cats to mime her maiden single, "Love Can Be".

In 1963, a lively vocal arrangement of The Shadows' "Dance On" took her to the edge of the Top Ten. This breakthrough coincided with a residency on ITV's long-running Stars And Garters variety show, broadcast on Saturday evenings to counterpoise BBC's Billy Cotton Band Show.

She had surfaced as Stars And Garters' main attraction when an upbeat and big-voiced overhaul of "Secret Love" came within an ace of topping the charts early in 1964, and an album, 16 Hits From Stars And Garters, was a moderate success during a year that closed with Kirby as Top Female Singer in the New Musical Express readers' poll. Backing musicians on Kirby recordings at this time included Jimmy Page and John Paul Jones, then awaiting their destinies with Led Zeppelin.

Two more Top 20 hits – "Let Me Go Lover" and "You're The One" – were followed by "I Belong", England's Eurovision Song Contest entry on 20 March 1965. While Kirby finished second, "I Belong" crawled to only No 36, and was her domestic chart farewell. Nevertheless, that summer's "The Way Of Love" penetrated the lower reaches of the US Hot 100 in the wake of a plug on the nationally-networked Ed Sullivan Show – and there was much airplay for her title theme to the BBC drama Adam Adamant Lives.

By then, hits had become secondary to TV viewing figures: a spot on 1965's Royal Command Performance and two prime-time BBC series, The Kathy Kirby Show and Kathy Kirby Sings. Tellingly, however, her guest list was dominated by such as The Beverley Sisters, Lonnie Donegan, Billy Fury, Adam Faith and others likewise disenfranchised by the beat boom.

Like Faith, Kirby was wondering about a future as a film actor, but this progressed no further than discussions. And Ambrose's managerial arrogance and old-fashioned values so annoyed BBC and ITV executives that TV appearances had petered out by 1970, when revivals of Kay Starr's pre-rock'n'roll "Wheel Of Fortune" and Frank Sinatra's "My Way" indicated a sense of retrospection and prefaced Kirby's "wilderness years".

Confused by post-Ambrose administrative chaos, Kirby was embroiled in writs for breach of contract,cash-flow problems and a steady gnawing away of work with little peaks and troughs. Yet "house full" signs would still go up, and she was kept in the public eye with occasional showcases like an assured recital in 1974 on ITV's Wheeltappers And Shunters Social Club, that, like Stars And Garters, flashed the beery joviality of a pub into your living room.

Less welcome was publicity centred on her divorce from the policeman-turned-journalist Frederick Pye;a spell in a mental hospital in 1979 after arrest for an unpaid hotel bill (of which she was innocent); and her cohabitation with another woman. Next, Kirby sold a three-edition story of her downfall to a Sunday newspaper, and attempted a comeback in 1981 as an intermission act in a Kentish bingo hall. There was also a new single, "He", a recalibration of Charles Aznavour's "She".

"I'm not going to write off my career," she promised, "I've still got one asset left – my voice." This was true enough, but she amassed a new and younger thanks to an image that many regarded as the ultimate camp for a dissolving of outlines between "quality" and kitsch.

Kirby retired as a professional entertainer in December 1983 witha televised performance in a Blackpool theatre-restaurant. Her remaining decades were unremarkable inthe teeth of strange stories, mostconspicuously, one about her as aLondon down-and-out, sleeping in shop doorways.

In fact she dwelt in a South Kensington flat, eking out state benefits and dwindling returns from CD compilations like 1996's The Very Best Of Kathy Kirby, and giving infrequent – and articulate – interviews to such disparate organs as Record Collector and in spring 2009, the Daily Express. She may have salvaged some contentment, too, from continued interest exemplified by a musical play, Whatever Happened To Kathy Kirby?, from London's New Stagers Theatre Club in 1996, and the adaptation into a stage production of the 2005 biography, Secrets, Loves And Lip Gloss.

Kathleen O'Rourke (Kathy Kirby), singer: born Ilford, Essex 20 October 1938; married Frederick Pye (marriage dissolved); died 19 May 2011.