For those coming to Daoist ritual from a sinological background (as is likely)—and for those who recognize that if we are going to study ritual, that involves performance, which in turn involves sound—here’s a quick crash course. Indeed, it comes in handy for anyone—particularly for those whose concept of music and singing is based on either WAM or pop (see e.g. here and here).

Among all the ethnomusicological surveys of vocal music, the 3-CD set

• Les voix du monde: une anthologie des expressions vocales
  (CNRS/Musée de l’Homme, 1996),

with its detailed booklet, makes a precious introduction. A wide range of styles of vocal production is covered here:

• Techniques
  Calls, cries, and clamours
  Voice and breath
  Spoken, declaimed, sung
  Compass and register
  Colours and timbres
  Disguised voices
  Ornamentation
  Voices and musical instruments
  Employ [sic] of harmonics
• Polyphonies
  Heterophony
  Echoes and overlapping
  Drones and ostinato
  Parallel, oblique or contrary motion
  Chords
  Counterpoint and combined techniques.

Apart from a veritable smorgasbord [sorry, been writing too many blurbs] of amazing audio tracks from all over the world, the booklet contains valuable notes, a glossary, and tables such as “Different forms of polyphony” in graphic form:

For ethnic polyphony in China, see here.

Then all we need is to digest

• Bell Yung “The nature of Chinese ritual sound“, in Yung, Rawski and Watson eds., Harmony and counterpoint: ritual music in Chinese context, pp.13–31

and we’re all set to enter the fray…