In between the lines on 2003’s Hotel Paper, you can hear Michelle Branch going through the growing pains of young adulthood. Add the pressures of rising pop stardom to the mix and you pretty much have the essence of this solid sophomore release. With the help of producer John Leventhal, Branch ventures into bluegrass territory (“Love Me Like That,” a duet with Sheryl Crow), dips her toes into swampy sounds (“Empty Handed”) and flirts with sultry R&B (“Desperately”). Branch passes through a battery of broken and thwarted relationships, with the stinging “Are You Happy Now” and the aggrieved “Breathe” carrying the most emotional charge. More bittersweet are thoughtfully yearning tracks like “It’s You” and “One of These Days.” At various points, Branch sounds like a better-mannered Avril Lavigne or a less-genteel Jewel. For all its studio polish, Hotel Paper sounds like a transitional work by an artist still in the throes of self-discovery — in fact, that’s part of its charm.