After Cassidy's death, local folk singer
Grace Griffith introduced the Blues Alley recording to Bill Straw from her label,
Blix Street Records. Shot at Blues Alley by a friend with a camcorder the same night the album was recorded, Alexis Petridis in
The Guardian wrote, "There's an undeniable emotional appeal in hearing an artist who you know died in obscurity singing a song about hope and a mystical world beyond everyday life".
Paul McCartney and
Eric Clapton were among her newfound fans. Jazz critic
Ted Gioia writes, "You might be tempted to write off the 'Cassidy sensation' ... as a response to the sad story of the singer's abbreviated life rather than as a measure of her artistry. But don't be mistaken, Cassidy was a huge talent, whose obscurity during her lifetime was almost as much a tragedy as her early death."
Songbird has since achieved significant chart success in Europe. It is certified six times
platinum in the UK with 1,840,000 copies sold. Although relatively unknown in the US at first, the album was eventually
certified gold. In May 2001,
ABC's
Nightline in the US broadcast a short documentary about Cassidy, a labor of love from
Nightline correspondent
Dave Marash who was a fan of her music. That weekend all five of Cassidy's albums occupied
Amazon.com's best sellers list top spots. The
Nightline episode was rebroadcast three times and producer
Leroy Sievers has said that it was "probably the most popular Nightline ever". In December 2000, a nine-minute segment on
NPR resulted in a similar sales surge, with five of the top seven spots going to Cassidy. Since
Songbird, several other CDs with original material have been released:
Time After Time (2000),
Imagine (2002) and
American Tune (2003). Cassidy's cover of
Time After Time was featured on the 2003 soundtrack CD of the popular superhero television series
Smallville.
Word of mouth and internet fan sites have played a large role in Cassidy's success. In 2005
Amazon.com released a list of its top 25 best-selling musicians, with Cassidy in fifth position behind
the Beatles,
U2,
Norah Jones and
Diana Krall. In 2008 another new album,
Somewhere, was released. Unlike previous albums which had contained only cover songs, this release included two original songs co-written by Cassidy. An acoustic album,
Simply Eva, was released in January 2011. In March 2023, the album
I Can Only Be Me was released, which featured new orchestrations by the
London Symphony Orchestra. The album debuted at number 9 on the UK Official Albums Chart. In an interview with
The Independent, Cassidy's former bandmate and arranger Chris Biondo said, "Eva had a fantasy of one day having a full orchestra back her up [...] to her, that was the greatest place you could be musically."
Audio restoration technology developed by filmmaker
Peter Jackson was used to lift Cassidy's voice from her original recordings and the orchestrations were produced in 2021. ==Unofficial releases==