The Indigo Girls [ tickets ] have assembled a spring/summer trek to support their forthcoming album, "Poseidon and the Bitter Bug."

The outing, which currently comprises stops in 20 US cities, gets under way April 4 in Palm Springs, CA, and then jumps over to the East Coast and Midwest for the remainder of the month. In May, the Indigo Girls have a two-night stand in Edmonds, WA, and they'll head east once again in June for a few more performances. Details are listed below.

"Poseidon and the Bitter Bug," due March 24, will be available as a full-band CD as well as a separate deluxe package with a second disc that features an acoustic version of the entire album. The set is Emily Saliers and Amy Ray's 11th studio album together and marks their first release on their own IG Recordings label.

"I feel a great sense of freedom in finally being rid of the major-label world," Ray said in the duo's bio. "It's been a burden for a while for me. I felt an honesty and sincerity making 'Poseidon,' because I fully believe in independence."

"It feels liberating and centering, even in the midst of change," Saliers added.

The new album reunites the Indigo Girls with veteran producer Mitchell Froom (Elvis Costello, Paul McCartney), who turned the knobs for their previous release, 2006's "Despite Our Differences." That set, which peaked at No. 44 on The Billboard 200, represented the Girls' 20th anniversary of performing together.

Froom helped to bridge the gap between Ray's and Saliers' songs on "Poseidon" as it was recorded in a whirlwind three-week session in Atlanta, according to their bio. The Grammy-winning folk-rockers wanted to keep a sense of spontaneity and discovery as they explored new approaches to melody, harmonies and rhythm in the new material. A couple of the tunes are being previewed at the Indigo Girls' MySpace page.

Before they hit the road, the duo will take to the high seas on the seven-night Cayamo Cruise, which sets sail from Miami this Saturday (2/28) and stops in several Caribbean ports. The Norwegian Dawn ship will be filled with folk, blues and Americana music from a host of artists including Lyle Lovett, John Hiatt and Patty Griffin.