Complex sentence: In 1941, the United States Navy arrived on Trinidad, and the panmen, who were associated with lawlessness and violence, helped to popularize steelpan music among soldiers, which began its international popularization.
Split into simpler sentences: In 1941, the United States Navy arrived on Trinidad. The pannists, who were associated with lawlessness and violence, helped to popularize steelpan music among the soldiers, which began its international popularization.