That can be a problem when a band has been successful for 15 years. Trying anything new or experimental can be risky, even if you have a loyal and enthusiastic fan base like the Indigo Girls. Some risks work, like U2 and Madonna’s shifting sounds over the decades, but the Indigo Girls’ new sound has been less of a hit.

Departing slightly from their more folksy roots, the Girls open All That We Let In with the righteous boom of the Hammond B-3 organ. Then they experiment with a ska beat before slipping back into their more familiar sound. There is no clear hit like “Closer to Fine” or “Romeo and Juliet” on this album, but I still liked “Fill It Up Again” for it’s deep resonating organ and cello, and “Dairy Queen” for its juicy lyrics. This song is most reminiscent of their earlier hits.

The second track, “Heartache for Everyone,” has the accessible storytelling songwriting that reminds me of my favorite Indigo Girls song, “Hammer and a Nail.” On top of these evocative lyrics, the Girls try out a rollicking ska beat. I really enjoyed this as a step away from the stereotypical strummed guitar and drumming-circle-inspired rhythm that is usually incorporated into Indigo Girls songs.

There are great new directions in the Indigo Girls sound, but the album doesn’t follow through on its promise. They marry new beats and instruments with their already fantastic guitar work, lyrics and harmonizing, but they don’t commit to this new direction and switch back to their patented sound by the third song. There is barely a chance to get excited about the band’s fusion of new styles with their strong folk lyricism and vocals.

Even worse, they bring in dreary, dirge-like tunes right in the middle of the album with the title song “All That We Let In” and “Tether.” These are woeful, activist-statement songs that easily become skippers, those oddballs on a CD that you always fast-forward through.

But before all you diehard Indigo Girls fans fall into despair, there are a couple of good reasons to get this album. The artwork on the album is all done by Jaime Hernandez of Love & Rockets comic book fame. Jaime and his brother Gilbert create beautiful graphic novels that feature Latinos and punk rockers in various slice-of-life situations. Two of their most famous characters are Hopi, a queer woman, and Maggie the Mechanic, her sometime girlfriend (Maggie is pictured on the cover). If you are a Love & Rockets fan, you will want to add this album to your collection for the artwork alone.

But more importantly, All That We Let In comes with a DVD of live performances recorded at The Bottom Line in New York City last December. You can watch versions of “Dairy Queen,” “Fill It Up Again,” “Come On Home,” and “Perfect World,” as well as their well-loved “Kid Fears” and “Galileo.”

Check out the Indigo Girls’ tour dates at indigogirls.com or buy the album now.