The Indigo Girls, winners of the 1990 Grammy Award for Best Contemporary Folk Recording, will be performing Tuesday at the Rialto Theatre. The celebrated duo of Amy Ray and Emily Saliers has been recording and touring together for more than 25 years.

Ray was born in Decatur, Ga., and met Saliers in school. They started performing together in their teens, and recorded their first full-length album, Strange Fire, in 1987. Their breakthrough came in 1988 when they were signed by Epic Records. In the same year, they released a self-titled album that resulted in two Grammy nominations and one win in 1990. Fourteen albums and 22 years later, they are still going strong.

Similar to their past work, their latest release, Beauty Queen Sister, is an album with a wide range of lyrical subject matter. They touch on many issues such as technology, love, and the mass death of red-winged blackbirds in Arkansas. In the song “War Rugs,” they even delve into the Arab Spring and the perceptions Americans tend to have regarding foreign affairs. The depth of their material and the smooth rhythmic transitions throughout the album make for a very enjoyable listen.

Their individual approach to songwriting creates a compelling flow to the album, with the stylistic characteristics of Ray and Saliers audible to the trained ear.

“We write totally separately, which gives us creative space. When we are starting to think about doing a record, we’ll get together and start trading songs, learning each others’ songs, working on harmonies and guitar parts. At that point, it becomes an Indigo Girls song,” said Ray.

Both Ray and Saliers are very politically active and are heavily involved with many charitable efforts. They have given their time and backing to groups concerned with environmental protection, the closure of Guantanamo Bay, Gulf Coast recovery and abolition of the death penalty. Additionally, they are founding members of the organization, Honor the Earth, which is working to build a sustainable economy for Native Americans.

Their activism is not limited to political motivations, however. In the late 1980s, Ray launched a non-profit record label that is still active today in supporting aspiring independent musicians.

The duo’s spirit of activism will be on display at the show in Tucson, as they have welcomed several immigration reform groups to table at the event to raise awareness of upcoming actions in the Supreme Court surrounding SB 1070.

Tuesday’s concert will feature a rock ‘n’ roll opening, with The Shadowboxers kicking off the evening.

“They’re amazing musicians, great songwriters, just out of college,” said Ray. “We’ll have a rock band part of the show, which will be really fantastic.”