After you set a commentary on East Timor to a disco beat-as Shakira did on "Timor," from her 2007 album "Oral Fixation"-any future musical endeavor inevitably seems less ambitious. Now Shakira is back with a modern disco track called "Loba," the Spanish version of "She-Wolf," her first single from her fall album. Though the song's wolf cries and panting noises are a little goofy, it's sure to get the Colombian singer's die-hard fans howling right along on the dancefloor. Its infectious groove rides a funk bassline, pulsates like a wild animal's heartbeat and plays perfectly to Shakira's ability to sing fast, crowded phrases in a way that forces the listener to pay attention. It's an unselfconsciously sexy, stylish ode to a woman on the prowl.