The qualities of a vocal genius don't always become clear when she's singing classic material.

Often as not, her abilities to both personalize and transcend a lifeless song with a stellar performance reveal the character behind the singer.

Both Billie Holiday and Otis Redding excelled no matter what they were recording, whether it was a timeless standard or a studio throwaway.

This collection of Amy Winehouse material, released to coincide with the first Christmas season after her death in July 2011, does not contain a strong set of material.

Besides the covers, which are well chosen, originals "Between the Cheats" and "Best Friends, Right?" and "Half Time" should not have survived the cut if Winehouse had been around to wield her veto power.

But if the songwriting isn’t strong enough to make listeners confuse this with a Back to Black follow-up, the productions and performances are up to her high caliber.

Salaam Remi and Mark Ronson handled virtually all of the production work, while these performances by Winehouse are just as strong as she showed on Frank and Back to Black.

Thanks to the work of Remi and Ronson, the album is also strikingly uniform; only the songwriting and prevalence of covers or "original versions" reveal that this is a posthumous collection.

Ronson's production on "Will You Still Love Me Tomorrow?" is towering, although he injects a little more drama into his chart than the song can support, while a skittering version of "The Girl from Ipanema" (nearly drum’n’bass at points) nearly reinvents a tired classic.

The recordings stretch from the beginning of her professional career to close to the end, but Winehouse is virtually always in strong voice; only on her Tony Bennett duet, “Body and Soul,” does she veer into self-parody.