Eva Cassidy possessed one of the finest singing voices of her generation, but few people outside her home town of Washington, DC, were aware of her until after her death on 2 November, 1996.

Several posthumous compilations and live recordings were released and after finally achieving radio play in the UK several years later her talent was recognised by the public, leading to huge international sales.

Eva Marie Cassidy was born in Washington on 2 February, 1963, into a family of amateur musicians. A child of precocious musical talent, her father taught her to play the guitar at the age of nine, and they and her brother performed together at family gatherings.

She was a shy, reserved girl during her high school days and would spend most of her time alone, painting or playing music. She sang with a band called Stonehenge while studying, before becoming a professional singer with Easy Street, a band-for-hire who sang at weddings and parties.

Her break came in 1986 when she produced the artwork for an album by a friend’s band, Method Actor. She performed guest vocals on the record and producer Chris Biondo was impressed enough to take her under his wing. He got her more work as a session singer and played tapes of her work to the likes of Chuck Brown and Roberta Flack, leading to prestigious collaborations.

In 1992, Chuck Brown and Eva Cassidy recorded an album, The Other Side, which featured classic soul covers, as well as a version of Over the Rainbow. They then began performing as a live act and Eva demonstrated a natural ability to adapt and blend her voice with any kind of music.

But throughout the 1990s she suffered health problems, hampering her performing and recording career. In 1993, she underwent surgery for malignant skin lesions on her back and three years later she was diagnosed with advanced melanoma during promotions for her debut live album, Live at Blues Alley.

The cancer started in her hip and spread rapidly through her body. By the time of her final performance at a tribute concert in September 1996, she had to use a walking frame to come on stage. She sang a duet with Brown and then performed What a Wonderful World solo.

Shortly afterwards she was admitted to Johns Hopkins Hospital in Baltimore and in less than two months she had died at the age of 33. That, however, is not where the Eva Cassidy story ends. In many ways it is where it begins.

In 1997, Eva by Heart, her only studio album, was released. She had recorded it because she was unhappy with the Live at Blues Alley performance. It contained 11 tracks, which were a mixture of traditional songs and contemporary blues numbers, and Miss Cassidy performed guitar, keyboards and cello.

The following year saw the release of Songbird, a compilation of her previous recordings that included classic renditions of Sting’s Fields of Gold, Fleetwood Mac’s Songbird, Curtis Mayfield’s People Get Ready and Over the Rainbow from The Wizard of Oz, which became her signature tune.

Songbird was a sleeper hit, reaching number one in the UK in 2001, thanks to support from Radio 2’s Terry Wogan and a Top of the Pops 2 screening of amateur footage of her playing Over the Rainbow. Success in Europe and America followed and the record went gold.

Six more posthumous albums were released and a number of bootlegs emerged. In December 2007, the blues singer Katie Melua recorded a ‘duet’ of What A Wonderful World with Eva which topped the singles chart.