Final answer:
The early 'armchair' scholars of the world music did not conduct their own fieldwork, which answers a) Fieldwork.
Step-by-step explanation:
In the early years of the study of world music, 'armchair' scholars did not do their own fieldwork. The correct answer to the fill-in-the-blank question is option a) Fieldwork. These scholars typically relied on the reports and the studies done by others rather than engaging in active or on-site research. This contrasts with the approach taken by modern ethnomusicologists, who often engage in participant observation and other forms of primary research to gain a deeper understanding of music in cultural contexts.