It’s been a popular subject ever since Gu Jiegang’s early study, published in 1928. The fine film-maker Patrice Fava has just made a handsome film about it too, for the Chinese Ministry of Culture—making an intriguing comparison with Ian’s own recent footage. Rather than idealizing, Ian takes a more personal ethnographic approach, documenting the changing nuances of people’s lives.
How wonderful to see Sidney Gamble’s footage from 1927! Visitors to Miaofengshan in 1925 included not only Gamble with Li Jinghan but also Gu Jiegang’s team. Even then, despite the wealth of devotional performing associations (huahui, xianghui etc.), they found hardly any performance of complex liturgical sequences. Gu Jiegang’s list of 99 associations making the pilgrimage in 1925 contains only one yinyuehui ritual association—which he, like most educated urbanites, would have assumed to be an entertainment group; his list mainly consists of huahui and “incense associations” (xianghui), mostly voluntary pilgrim groups from Beijing. On the Hebei plain, by contrast, the Houshan temple fair has many more ritual associations alongside the huahui. 
Along with scholars’ attention to the temple fair of Fanzhuang in Zhaoxian county,  a misleading image may arise of north Chinese religious life, whereby liturgical sequences performed by occupational ritual specialists and amateur sectarian associations are downplayed.
From my experience of ritual life around Beijing and on the plain to the south, the dominance of semi-secular “entertainment associations” at sites like Miaofengshan seems curious. I think, for instance, of the temple fairs on Houshan in Yixian county southwest of Beijing, so much less publicized in the media. Unlike on Miaofengshan and the other sacred mountain sites just north of Beijing, Bixia yuanjun is a minor deity in this region, which instead is dominated by the cult of Empress Houtu.
But the differences aren’t only their respective deities. The two major annual fairs of Houshan are also attended by vast throngs. Apart from the diverse huahui performing groups (martial arts, stilts, and so on) that one finds on Miaofengshan, amateur ritual associations from many villages throughout the area (our project through the 1990s) also make the pilgrimage. They perform devotional hymns to the patron goddess Houtu, as well as their solemn style of shengguan instrumental suites. The elders recall performing in full the “precious scroll” (baojuan) to Houtu—a lengthy process, though this may have lapsed on the mountain itself. But as I noted in Plucking the winds (p.363),
Despite considerable interest in village sects in imperial times and even until 1949, we find rather little on the observed performance of ritual. One scholar wrote laconically in 1948:
During the recitation of canons and divine rolls [viz. precious scrolls] musical instruments were probably used. In the country districts in North China there are still some similar organizations. They perform on musical instruments when they recite their canons.
Why write “were probably used” when he could have gone and observed them performing the scrolls?!
Houshan is also heavily patronized by spirit mediums, many of whom also have “precious scrolls” from which they perform devotional songs.
I note en passant that whereas the “tea-tents” on the route to Miaofengshan are precisely that, in the Xushui—Dingxing—Xiongxian area south of Beijing the Tea tent association is often an alternative name for sectarian groups like Hunyuan and Hongyang associations; and they perform complex rituals with vocal liturgy and shengguan instrumental music.
The more popular, quasi-secular entertainment groups tend to influence our image of north Chinese religious activity; the cliché is that ritual life is far more complex in the south than in the north. I don’t dispute this (my book pp.367–8)—some scholars of southern Chinese religion will ask “Where are all the grand jiao Offering rituals?” But we should bear in mind that in the north too, complex vocal liturgy, such as one finds further south in China, is widely performed by groups of occupational Daoist and Buddhist household ritual specialists and amateur ritual associations (see my In search of the folk Daoists of north China).
In other words, it’s another case of “customs differ every ten li” (shilidi butong su). Of course, whether or not we find complex ritual sequences, we still need to document all kinds of activity.
As I noted for Houshan and Baiyunshan, state departments compete with local interests for economic control of the substantial profits from such temple fairs.
There’s also a puzzle that I mentioned in In search of the folk Daoists. We know there were constant transmissions, in both directions, between Buddhist and Daoist temples in metropolitan Beijing and Tianjin (on the one hand), and (on the other) the myriad local temples and amateur sectarian ritual associations in the surrounding areas. But from our material so far it looks as if these exchanges were largely limited to the plain south, hardly in other directions—like northwest, in the case of Miaofengshan. I surmise that this is related to topography, trade links and transport. Northwest of Beijing the land is hilly and poor. The plain to the south, while also poor, was at least more accessible, and on trade hubs.
But there’s always more fieldwork to be done!