Katy B, "On a Mission" (Rinse/Columbia)

To hear what Katy B does so well, dig up "Hold Me," her collaboration with the Count & Sinden from their 2010 album "Mega Mega Mega." The beat is vibrant and sinister, all wobbly bass lines and clanging percussion. But atop it all Katy B sings smoothly and sweetly. Her soft voice turns a challenge into a seduction.

That's what this young singer's been doing for the past couple of years, mostly alongside DJ Zinc and Geeneus, the founder of Rinse FM, the onetime London pirate station gone legit -- ground zero for grime, dubstep and funky. "On a Mission," Katy B's solo debut, takes that crossover even further, turning each of those sometimes abrasive styles into soft beds.

Here she massages the visceral throb of dubstep, and on "Why You Always Here," it's funky, with echoes of its older cousin 2-step garage, that gets finessed. As a singer Katy B knows just how far she can push herself, but sometimes, in seeming sympathy, the production, largely by Geeneus and Zinc, tends softer. But on less challenging songs like "Go Away" and "Disappear," that leaves her with less to do, and it shows.

If Katy B were a more dynamic songwriter, it would help, but she can be wordy. And sometimes she's inflecting more than singing, especially when she slips into fake patois, as on "Hard to Get." The contrast is starkest on "Lights On," a duet with Ms. Dynamite, who knows how to laser-target her melodies. Here she fires darts, while Katy B glides in afterward to smooth over the damage.



Tori Amos, "Night of Hunters" (Deutsche Grammophon)

Amos's 12th studio album might not be the best of her career, but it's certainly the bassooniest. Diving headfirst into the instrumentation and compositional approach of classical music, "Night of Hunters" hews closer to "Peter and the Wolf" than "Little Earthquakes," as dark woodwinds constantly honk and erupt through the symphonic settings of Amos' songs.

The 72-minute result feels less like an opera than a ballet with lyrics standing in for the dancing. The story line involves shape-shifting spirit guides and Irish time travel to a land of ancient gods, all dismayingly in the service of what is at its core the tale of a bad breakup. If a songwriter goes all out with talk of fire muses, glass forests, and ancient tree alphabets, perhaps it shouldn't be because she's sad about a boy.

If it all seems a bit silly to you, then you probably haven't made it this far with Amos, anyway. Even so, there's a brief run midway through --from "Job's Coffin" to "Edge of the Moon" -- where Amos' ambition settles a bit, and the other instruments serve her piano rather than each chattering along in its own conversation.

But the bulk of the album's melodies and arrangements are too busily discursive to hum after the fact, making it tough for "Night of Hunters" to do what Amos set out to do: haunt the listener.