The Denver Center is a-humming. In the theater company’s largest house, Emma Woodhouse — to her own gentle comeuppance — is winking her way through Kate Hamill’s delightful adaptation of Jane Austen’s “Emma.” (See if before it closes Sunday.) Downstairs in the Singleton Theatre, things are positively loopy. Or rather brilliantly looping, as a young, Latina music-maker sets about crafting a mixed tape of her life in the hip-hop-influenced “Where Did We Sit on the Bus?,” directed by Matt Dickson.