Rilo Kiley Gets Even More Adventurous

The best song on Rilo Kiley’s fourth studio album, “Under the Blacklight,” is a simmering plateful of Southern soul called “15.” It’s a delightfully crass little yarn with a stately horn arrangement, about a lonesome teenager and the “spider on the Web” who coaxes her from her keyboard. It’s not exactly what you’d call “classic” Rilo Kiley, since the foursome from the moneyed slums of Los Angeles only started doing its best “Dusty in Memphis” impression on 2005’s slickly produced “More Adventurous.”But the song sounds instantly inviting, a logical progression after three albums of increasingly sophisticated pop music, and a window into the group’s keen talent for reinvention.