Claudia Dumschat leads the singers and instrumentalists of the Church of the Transfiguration in an imaginative program that mixes all manner of beasties: Britten's Rejoice in the Lamb, Alan Ridout's George—A Fable, Judith Shatin's The Jabberwocky and selections from Gian Carlo Menotti's The Unicorn, the Gorgon and the Manticore.