Final answer:
Participant observation is the research approach where an ethnomusicologist learns to perform the music they study, central to the interdisciplinary field of ethnomusicology, which examines music within various social and cultural contexts.
Step-by-step explanation:
A research approach in which an ethnomusicologist learns to perform the music they study is known as participant observation. This method involves the researcher becoming actively involved in the cultural practice they are studying, in this case, music. Not only does it involve the observation of musical practices and social interactions within a given culture, but it also necessitates the active participation of the researcher in learning and performing the music. Ethnomusicology is a subfield of cultural anthropology that explores music within its social and cultural contexts. Researchers conduct fieldwork, immersing themselves in musical communities to better understand the people creating and experiencing music, the cultural significance of musical practices and performances, and the social dynamics at play. As an interdisciplinary field, ethnomusicology binds together diverse approaches, including historical, sociological, and anthropological perspectives to study the anthropology of music. Participant observation as a research method is fundamental to ethnomusicology, allowing the researcher to gain insight into the music-making process as an active participant, rather than a detached observer. This deep engagement facilitates a profound understanding of the music and its cultural importance from the inside out.