Mary J.

Blige had a productive 2014.

Early in the year, she linked with Disclosure for an alternate version of the U.K.

duo's "F for You" and performed with them in New York.

A few months later, there was the release of the all-Blige soundtrack for the comedy Think Like a Man Too, which consisted of new material but was neither presented nor promoted like one of her standard releases.

At some point, Blige signed to Capitol, and she took longtime collaborator Rodney Jerkins to England to work more with Disclosure, as well as with other emerging songwriters and producers, including Vibe cover star Sam Smith, Naughty Boy, and Emeli Sandé.

The move was evidently significant enough to warrant the album's title and the placement of the collaborators' names on the cover.

It's not that the changeup revitalized Blige.

The London Sessions just happens to have her best round of songs, productions, and performances since The Breakthrough, the 2005 album Smith references in one of several unnecessary testimonials and interview snippets placed throughout the sequence of songs.

A couple moments are stilted and there's some substandard songwriting, such as the woeful "I'll keep gettin' up, 'cause that's what I'm goin' to do/Gonna be the best me, I'm sorry if it kills you," from the otherwise fine "Doubt." The London Sessions nonetheless offers a sharp mix of duly aching ballads and substantive, highly detailed club tracks that are in the soul-rooted lineage of classics she has referenced, covered, and emulated throughout her career.

Blige sounds as comfortable as ever over the scuffing percussion, prodding synthesizers, and even the noodling clarinet heard, at various points, in the likes of "Right Now," "My Loving," "Pick Me Up," and "Follow." The songs explore themes familiar to Blige's listeners, yet little is less than fresh.

Among the ballads, the Sandé collaboration "Whole Damn Year" is the most striking, disarming in its depiction of recovering from emotional and physical abuse, while "Therapy," one of four songs made with Smith, is surprisingly understated, seemingly inspired more by Anthony Hamilton's Southern gospel-soul.