Devotees of some bands expect their idols to keep evolving musically, to take risks and to try different directions.

Other fans want their favorite bands to stay as they are, continuing to do what they do best, in the same ways, forever. For listeners like this, the Indigo Girls [ tickets ] almost always deliver, and they certainly have with their ninth studio release, "All That We Let In."

Armed with their folk rock tools (among them: multiple guitars, an accordion, strings, a Wurlitzer, conga drums and Joan Osborne) and ready to take on their regular subjects (the environment, warmongers, heartbreak and regret), Amy Ray and Emily Saliers again provide a healthy supply of invigorating tunes.

Saliers' "Fill It Up Again," "Free In You" and the title track all display her ability to pit lyrics about the good and bad in love against sweet, mostly upbeat melodies. Meanwhile, Ray combines thoughts about her activism and community in almost every song she pens, though her simple break-up song, "Dairy Queen," may be her best here.

There are a few new things in this mix. The ska beat in "Heartache for Everyone" is reportedly influenced by Ray's interest in The Clash, and there's an Elton John-like piano behind the rousing final song, "Rise Up." It's enough to show that even though the Girls may continue to tread familiar waters, they've got plenty of creativity to keep them--and their fans--going for albums to come.