Call Leona Lewis a diva of the old-fashioned variety: a singer who uses her rafter-rattling voice to dramatize female suffering. On her second album, the U.K. belter delivers synth arrangements that arc skyward, toward Simon Cowell's mountaintop redoubt. Lewis is technically flawless, but behind lyrics about "the scars on my heart," there's little personality — you miss a little of Mariah and Whitney's supersize ego.