The Indigo Girls, also known as Emily Saliers and Amy Ray, have been playing music together since they were in high school. For the past 19 years, the Atlanta-based duo has been producing critically-acclaimed contemporary folk music, and has sold millions of albums. All That We Let In is the newest album from the Indigo Girls.

The Indigo Girls first started blending folk, rock and pop in the early 1980s. Moving from school talent shows to Atlanta-area clubs, they recorded their first songs in Amy Ray's basement. Signed to Epic Records in 1988, they won a Grammy Award for Best Contemporary Folk Recording, and were nominated for Best New Artist. They continued to gain new fans throughout the 1990s, and were headliners at two of Sarah McLachlan's Lilith Fair tours, which highlighted women artists.

The Indigo Girls' latest album, All That We Let In, adds elements of ska, southern rock, Celtic touches and a good amount of classic rock guitar lines, along with contemporary folk. Singer and songwriter Joan Osbourne makes a guest appearance on several tunes.

The duo has been known for their activism concerning environmental issues and the preservation of the sacred sites of Native Americans. Amy Ray's tune Cordova, written over a five-year period, is about some activist friends in the Native American community who passed away.

"You're working so closely together and then you fall in love, but you don't know if you're falling in love with the person or the revolution. The human dynamics fascinate me," Amy comments.

The Indigo Girls have always maintained a close relationship with their fans. Last August, during the largest power outage in North American history, they didn't disappoint their New York City audience in Central Park. Relying on generators with limited power, they played a 45-minute show for their loyal supporters, who were asked to move close to the stage. In October, they returned to the park and made up for their abbreviated concert by playing a 20-song set.

The Indigo Girls have just wrapped up an engagement with the Atlanta Ballet and Symphony, where their songs were set to modern dance choreography. They're about to embark on the second leg of their U.S. tour, which will run through May. In the middle of the year, they plan to launch a larger-scale tour, with a full back-up band, that will include information booths about voter registration and environmental issues.

Amy Ray says the first single from All That We Let In is "about having a good time and not paying attention to what's going on in the world, and then realizing you can't do that.

You have a responsibility to be accountable," she says.