The surprise breakthrough of Les Nubians version of Sade's mellow and soulful ballad, "The Sweetest Taboo," helped their American debut, Les Princesses Nubiennes to achieve a higher position on the Billboard charts than any other French-language album in the previous decade.

The sweet, seamless harmonies achieved by sisters Helene and Celia Faussart made an already hypnotic song intoxicating.

So, it is no surprise that in their follow-up effort, One Step Forward, that those harmonies sung in the same soft, rounded, African-inflected French language would charm in the same way.

What seems less successful are the English language efforts, especially the radio-friendly first single, "Temperature Rising," which features a stylish, if somewhat out-of-place rap delivered by Talib Kweli that seems grafted on.

The sisters' trademark smoothness is diminished when they sing in English, which becomes even more obvious on their reggae-flavored duet with Morgan Heritage.

Here the sisters flow from English to French throughout the song, and you can almost feel them tensing up and straining whenever they switch.

Thankfully, though, such stumbles are few and far between on the album.

Recorded in Jamaica, One Step Forward as a whole has a lulling, laid back, tropical feel that seems to effortlessly encompass jazz, African rhythms, R&B, pop and electronic sounds.