Amy Ray and Emily Saliers started performing together in high school and scored a Grammy Award with their platinum-selling self-titled debut release. More than 15 albums later, the Indigo Girls keep a busy recording and touring schedule on the strength of their distinctive but complementary singing and writing styles and a catalog of tunes that have become contemporary classics: “Galileo,” “Closer To Fine,” “Hammer and Nail” and “Least Complicated,” to name a few. Their new album is Indigo Girls Live With the University of Colorado Symphony Orchestra, a 22-song set of fan favorites, deep cuts and tracks from their 2015 album, One Lost Day.