Final answer:
Harry T. Burleigh collaborated with European composer Antonín Dvořák, sharing African American spirituals and folk music, which influenced Dvořák's 'New World Symphony'.
Step-by-step explanation:
Harry T. Burleigh worked with the European composer Antonín Dvořák while the latter was teaching in the United States. Burleigh, an African American composer, was a key figure in the development of American music and played a significant role during his working relationship with Dvořák by sharing with him the African American spirituals and folk music. This collaboration influenced Dvořák's work, particularly his 'New World Symphony', which integrates elements of American music, demonstrating the rich cultural exchange that took place between Burleigh and Dvořák.