In 1984, after he had left drama school, Ball's first part was in "Godspell" at Aberystwyth Arts Centre, after which he worked for a few months in rep in Basingstoke, but his first major break was a star part in the production of "The Pirates of Penzance" at Manchester Opera House; at an open audition he was selected from about 600 applicants who formed a queue to do singing, acting, and dancing interviews, which were held in three separate rooms. His next important role came when Cameron Mackintosh cast him as Marius in the original London cast of "Les Misérables", but he caught glandular fever and he took six or seven weeks off sick to recover from the associated tonsillitis and post-viral fatigue. When he returned to work he was still suffering from fatigue, and began to get on-stage panic attacks — overwhelming anxiety, a rapid heartbeat, sweating, and problems with vision. These also started happening at other times, such as when he was going to work. For most of the next nine months he lived alone in his flat feeling depressed; he did not seek therapy and left "Les Misérables".