Melding the simple boogie of American heartland rock with the epic excesses of prog-rock, Kansas scored a pair of monster hits in the ’70s, “Carry On Wayward Son” and “Dust in the Wind,” and a handful of lesser singles that continue to clock significant airplay on classic rock stations, ensuring the band’s viability as a touring act. Last time they stopped in Milwaukee, they played with a 38-piece symphony, but tonight’s 10 p.m. set at the M&I Classic Rock Stage promises to showcase the band’s stripped-down side.