Amy Winehouse Lioness: Hidden Treasures features 12 tracks recorded by the late singer in various stages of her life handpicked by her producer friends Mark Ronson and Salaam Remi.
"It has been hard, but it has also been an amazing thing," Remi told The Sun. "Amy was a gifted girl.
"I believe she has left something beyond her years. She has put a body of work together that will inspire an unborn generation."
According to the publication, one song was recorded while Winehouse was under the influence of heroin and another - called 'Between the Cheats' - tells of her divorce from Blake Fielder-Civil.
Other highlights include covers of 'A Song For You' by Winehouse's favourite artist Donny Hathaway on which she plays the guitar, and 'Will You Still Love Me Tomorrow' by Carole King, which was produced before the star began battling drink and drug addictions in 2004.
Winehouse's last recording, Tony Bennett duet 'Body & Soul', also appears, along with demo versions of songs from Frank and Back to Black.
Lioness: Hidden Treasures has received the backing of Winehouse's parents Mitch and Janis, who both dismissed previous fears that a posthumous album release could ruin the 'Back to Black' singer's legacy.
"I spent so much time chasing after Amy - telling her off - that I never realised what a true genius she was," Mitch commented.
"It wasn't until I sat down with the rest of the family and listened to this album that I fully appreciated the breadth of her talent. From jazz standards to hip-hop songs, it took my breath away."
Janis, meanwhile, identified an "incredibly beautiful" song called 'Halftime' as her favourite of the collection.
"Had the family felt this album wasn't up to the standard of Amy's others, Frank and Back To Black, we'd never have agreed to release it," she added. "We believe it will stand as a fitting tribute to her musical legacy."
£1 from every sale of Amy Winehouse Lioness: Hidden Treasures will go to the foundation established in her name by Mitch.
The album does not include any tracks from her unfinished third studio LP, which was tipped for release after her death on July 23.
The full tracklisting for Amy Winehouse Lioness: Hidden Treasures is as follows:
- 1. 'Our Day Will Come' (reggae version)
- 2. 'Between the Cheats'
- 3. 'Tears Dry'
- 4. 'Wake Up Alone' (demo)
- 5. 'Will You Still Love Me Tomorrow'
- 6. 'Valerie' (demo)
- 7. 'Like Smoke' (featuring Nas)
- 8. 'The Girl from Ipanema'
- 9. 'Halftime'
- 10. 'Best Friends'
- 11. 'Body and Soul' (with Tony Bennett)
- 12. 'A Song for You'