At least this calculatedly familiar show leaves you humming all 22 melodies--more than can be said for many Broadway exports, where you're lucky to remember one. Benny Andersson, Bjorn Ulvaeus, and Catherine Johnson's Mamma Mia! remains an elaborate if distracting excuse for a simulated Abba reunion, as a bride seeks her real father while her mother readmits love into her heart. Oddly, the songs in the connect-the-hits plot retain their lyrics, which can make the numbers preposterously inappropriate for the story at hand. But of course these terrific tunes can't be changed; they're the cause--for many, reason enough--for celebration. The constant revelation with this show is how its true-believer fans come to life during the megamix finale, when the principal performers don glitzy spandex and big wigs to re-create Sweden's gift to bubblegum pop. Through 12/26: Tue-Thu 7:30 PM, Fri 8 PM, Sat 2 and 8 PM, Sun 2 and 7:30 PM. Wed 12/8, 2 and 7:30 PM. Holiday schedule varies; call for information. Ford Center for the Performing Arts, Oriental Theatre, 24 W. Randolph, 312-902-1400 $37-$83.