“New Dances at Juilliard,” a yearly project, matches pre-professionals with established choreographers. Ravishingly accompanied, in part, by live music, the results of this creative process were heartening. All four choreographers—Janis Brenner, Susan Marshall, Ronald K. Brown, and Robert Battle—made mood-tinged abstract pieces. Distinguished by clear, firm construction, they displayed an astute understanding of the newcomers’ formidable gifts and limited experience plus well-nigh palpable affection and respect for the rising generation. The dancers, in turn, lent the undertaking youth’s inimitable freshness and power—and a richly textured way of moving that seems to be a Juilliard trademark. The standout number was Marshall’s Working Memory, which may well reflect a dancer’s life. In its bleak arena, figures consult score-like tomes, and in carrying out their instructions, inevitably collapse, fall, and doggedly rise to try again, experiencing fleeting moments of succor or joy.