Some may (wrongly) imagine folk cultures as a kind of “living fossil”, but in China, thankfully, few yet seek to recreate the performances of the past in arid concert halls. Or at least it’s still a small industry, such as attempts to recreate Tang music… And so far it’s been an exercise performed, with little or no concern for historical style, not by folk musicians but by urban educated pundits and conservatoire performers, trapped within their modern preconceptions.  Folk musicians, like symphony orchestras (at least until recently), are quite happy working within their evolving tradition, without agonizing over “preserving” some supposed “authenticity”.
Scholars of Daoist ritual aren’t necessarily seeking to “hear a centuries-old piece of music as it was heard when it was composed”. What they may do, though, is silently equate living performance with that of the Tang or Song dynasties. From my book, p.369:
While Lagerwey’s fine accounts of Daoist ritual in Taiwan occasionally suggest clues to changing ritual practice in modern times, “our primary interest […] is less to give a complete description of actual practice […] than it is to analyse the deep structure of that practice” (Lagerwey 1987: 91)—an influential perspective that tends to lead to the noble yet arcane goal of studying texts as evidence for the ritual structures of medieval times.
And Daoist scholars do sometimes seek to recreate rituals from the memory of elderly Daoists, as in Shanghai—evidently a worthy “salvage” project, albeit without reference to the changing social context since their youth.
Context and style have changed far less than with WAM—but they have changed. Apart from more general social changes, early music studies influence me in noting all kinds of changes in the Li band’s performance practice since the 1930s (my book pp.358–60):
Recently they have reduced the personnel from seven to six, discarding one guanzi, and the dizi has hardly been needed since the 1990s,
Turning to rituals, since current practice is dominated by funerals, this might at first seem to be their tradition. But they clearly recall a tripartite system of funerary, earth, and temple rituals; even if the latter two are now virtually obsolete, it is clear from their manuals. Thanking the Earth, once their most frequently performed ritual, has been lost since 1954; people can now afford to commission it again, but don’t. Though some temples have been restored, those holding fairs are fewer, and ritual sequences have been simplified along the lines of funerals. Three-day funerals are less common; and when they are held, the old sequence has become simplified and homogenized.
As to ritual segments within funerals, some were already largely obsolete by the 1940s, while others could still be performed in the 1990s but weren’t. Some, like Communicating the Lanterns and Judgment and Alms, have been radically simplified into mere symbolic tokens since the 1990s. Some—such as Dispensing Food or those from the “outer five rituals” like Crossing the Bridges—have become virtually obsolete since the 1950s; Li Qing and his colleagues could perform Opening the Quarters and the Pardon, but his disciples have hardly needed to do so. Yet others were probably rare even by the 1930s (Presenting the Memorial, Roaming the Lotuses, Smashing the Hells) or already lost by then (Offering Viands). Though segments have been adapted under Li Manshan’s leadership, his elders were already doing so long before.
As for the ritual manuals, we must take care to avoid some timeless ideal depiction. As the repertoire shrinks the manuals are not needed at all, but even before the 1950s many segments were performed without them. Li Qing probably didn’t know how to perform some of the rituals whose texts he copied in the 1980s. The lengthy chanted scriptures—around half of the total collection of manuals—were indeed placed on the table during performance, yet Li Qing and his colleagues could recite them so fluently that they barely needed to glance at them; now they are no longer expounded.
Along with the reduction in ritual repertoire, all three performance styles have been reduced—vocal liturgy, percussion items, and melodic instrumental music. The current repertoire of hymns is smaller than that in Li Qing’s score, so where there is a choice (as for Delivering the Scriptures and Transferring Offerings), that choice has become smaller. The “words of blessing” for Thanking the Earth are no longer performed, and fewer shuowen recited introits and mantras for offering paper are used. As the rituals that require them have been lost, instruments like the chaoban tablet, muyu woodblock, and qing bowl have fallen silent; and the dizi flute is no longer part of the melodic ensemble. The lengthy instrumental suites for Thanking the Earth and temple fairs are hardly performed, and the old variety of scales has been reduced. The repertoire of percussion items has also diminished.
But I don’t seek to lead the Li band towards reconstructing the practice of the 1930s, still less that of earlier ages.
Two small examples. Chatting with Li Manshan, I have mentioned how the “classic” instrumentation of the melodic ensemble that accompanies Daoist (and Buddhist) ritual around Beijing, and elsewhere in Shanxi, includes a ten-gong frame of yunluo—like Wutaishan further south, and Tianzhen (adjacent to Yanggao), where they still use a seven-gong frame, the lowest row missing. If Li Manshan felt so inclined, he could order a ten-gong frame, and “restore” it to the ensemble.
“But we don’t know how to play it!” he comments, reasonably.
“Even I could teach you!” I point out impertinently, adducing the common folk saying,
“A thousand days for the guanzi, a hundred days for the sheng; you can learn the yunluo by the fifth watch”.
But one reason I won’t press the idea is that, despite the Tianzhen yunluo, even his father didn’t recall a ten-gong frame. I may surmise that it must surely have been part of the band at some stage before the 20th century, but I don’t interfere. Li Manshan isn’t in the business of recreation, and neither am I. I describe, not prescribe—except when I transplant them to the alien context of the concert hall, when my subliminal influence, and their own perceptions of the demands of the situation, seem to prompt them to perform with somewhat more grandeur than in the casual current conditions of rural funerals.
Another instance: in my book I note that since 1953 there have been hardly any patrons commissioning the two-day Thanking the Earth ritual. Li Qing’s colleague Kang Ren (b.1925) described its sequence to us before his death in 2010; Li Manshan and Golden Noble were interested enough to take notes, but can’t mobilize their local patrons to invite them to do it. Most of its components could be recreated, if there were demand. But there isn’t. This is the kind of thing that Daoist scholars might commission specially as a worthwhile salvage project, but my gentle suggestions lead nowhere. Some other obsolete or rarely-performed funerary rituals (my book ch.13) could also be restored, just about. But local patrons wouldn’t welcome it—it’s inconceivable, until such time as they suddenly do request them.
 A rather different, if minor, case is recreations of obsolete rituals at the behest of local Bureaus of Culture. Such initiatives feel artificial, and scholars should take care both to point out the conditions under which they are made and to avoid silently equating them with some “authentic” folk practice. See e.g. Overmyer, Ethnography in China, pp.287–95.