Complex sentence: However, Verdi kept at least a third of the score at Busseto and was to bring it with him when he arrived in Venice for the rehearsals on 19 February and would continue to refine the orchestration during the rehearsal period.
Split into simpler sentences: However, Verdi kept at least a third of the score at Busseto. He brought it with him when he arrived in Venice for the rehearsals on 19 February and would continue to refine the orchestration during the rehearsal period.