Building on the solid foundation of 1999’s acclaimed Spirit Child (J Curve), former U.S. Jazz Ambassador Lenora Zenzalai Helm is back with the substantially sumptuous Precipice (Baoule). With a voice like buttery suede, the multitalented Chicago native places her indelible stamp on seven standards and five self-penned compositions. The originals range from serviceably pedestrian (“Falling Down”) to dazzlingly outre (the boldly colored title track blended with an inventive tone-poem treatment of Coltrane’s “Wise One”). Most impressive is the nicely chilled “Autumns” (co-written with Branford Marsalis), heavy with the pungent aroma of self-incriminating disappointment. Among the more familiar fare, Helm’s languid “Every Time We Say Goodbye” is at once tremulous and predatory, while her “But Not for Me” remains a delicious shade brighter than the usual dark-as-pitch interpretations. Her light, lilting “Says My Heart” amounts to three-and-a-half minutes of silken self-gratification, and her simmering “Cheek to Cheek” reminds us that the Berlin classic is meant to radiate with sexual anticipation. Potent as such covers are, none can quite compare to Helm’s splendid exploration of Chick Corea’s “Highwire,” which retains all of the piece’s swooping majesty without ever compromising its dreamy undercurrent.