Powerful score and effective staging propel story of conjoined twins, though it struggles for emotional connection

For a musical about true-life conjoined twins Daisy and Violet Hilton, the strange and stirring Side Show has a nagging habit of losing its grip. Chalk it up to dramatic inconsistencies and thin characterizations.  Even so, there’s a lot to like about the revised vision of this Depression-era biography that arrives on Broadway following a run in 2013 at the La Jolla Playhouse and earlier this year at the Kennedy Center. Beyond a laudably offbeat topic, two very good leading ladies and a shadowy, evocative design, this show’s most stunning jewels are brilliant songs by composer Henry Krieger and lyricist Bill Russell, who revamped the book with director Bill Condon. The voluptuous, lushly arranged score (new songs have been added and some have been dropped from the 1997 Broadway premiere, which ran 91 performances) boasts dark, moody streaks like “Come Look at the Freaks,” the opening song setting a creepy tone. There are cheeky and chipper vaudeville novelty numbers, like “One Plus One Equals Three” and “Stuck With You,” performed by the girls at a glue factory (wink, wink). “The Interview,” which finds the girls’ fame ascending, recalls a scene from “Dreamgirls,” another Krieger show.