Orson Welles' pioneering, influential cinema was imaginative, ambitious and technically daring. His baroque cinematic style created a dense moral universe in which every action had tangled--and usually tragic--human repercussions. Before his dramatic arrival in Hollywood, Welles had carved a considerable reputation in theater and radio. At 18 he was a successful actor at the experimental Gate Theatre in Ireland; at 19, he made his Broadway debut as Tybalt in "Romeo and Juliet....