Choreographer Miro Magloire presents his ensemble of dancers and musicians in a premiere set to John Cage's "Cheap Imitation," originally written for the Merce Cunningham company, along with repertory works to Mozart, Luciano Berio, and contemporary composers Richard Carrick and Beat Furrer.   Dancers are Sarah Atkins, Elizabeth Brown, Kristine Butler, Tracy Finch, and Amber Neff.   Musicians are pianist Melody Fader and violinist Doori Na.