In Chinese religious studies, fieldwork and historical study of texts should be complementary. While the changing ritual scene in rural north China over the past century has largely been left to musicologists, Cao Xinyu 曹新宇 (People’s University, Beijing) continues his fine work on the imperial ancestry of sectarian groups, setting forth from the seminal research of the great Li Shiyu, and studies like those of Ma Xisha and Han Bingfang (see here, on useful site for Qing history)—all similarly utilizing fieldwork.
Sects are a poor cousin to research on more open forms of institutional religion, but—like spirit mediums—an important part of the picture. While I constantly stress the sectarian connections of ritual associations on the Hebei plain, as a counterbalance to the current secular image portrayed by the Intangible Cultural Heritage, highly worthy of study is Cao Xinyu’s recent book
- Zushide zupu: Ming–Qing Bailian jiao shehui lishi diaocha zhiyi 祖師的族譜: 明清白蓮教社會歷史調查之一 [Lineage genealogies of sectarian masters: socio-historical fieldwork on the White Lotus Teachings in Ming and Qing, vol. 1] (Taiwan, 2016).
It’s high time to bring into contact the two strands of historical research and fieldwork on the modern fortunes of the bewildering variety of groups that we find around north China—such as Hunyuan, Hongyang, Huangtian dao, and Laofomen. This is a major task for fieldworkers, including music scholars. 
 For now I’ll leave you to compile your own lists for Western-language studies, such as Weller, Ownby, Overmyer, Palmer, ter Haar, DuBois, and so on—a valuable resource is the rubric in Philip Clart’s essential bibliography.