In olden days, Beck Center was the place where Kiwanis Club members and bowling ladies would go to attend revivals of The Odd Couple. In the last few years, it's gone through a miraculous metamorphosis, turning into the area's most vital and profoundly alive theater. Just this season, it's dazzled with Sondheim, goosed audiences with the giddy Zombie Prom, awed them with Ibsen, and won admiration with an admirable but misguided Arthur Miller production. To top it all off, it ended its season with a musical revue (Smokey Joe's Café) of undiminished polish, pizzazz, and high spirits. Special congratulations go to artistic director Scott Spence for helping to nudge this institution into a golden age.