Hello, Anne. I'd be delighted to help or collaborate in any way I can. The best way to be in touch is via my research site, www.earlymusicmuse.com, or my performance site, www.ipmusic.org.uk. I hope to hear from you when you're ready. :-)   

Mr Red - what David Carter said. No one else has mentioned Henry VIII, who wasn't in any sense medieval.

Lighter, I can't respond to your point because I can't make any sense of it. You seem to suggest we should play medieval music on modern instruments because modern instruments are more medieval than medieval ones. No one in the field talks about authenticity and haven't done for years: we talk about HIP - historically informed performance - because we know authenticity is a mirage and authenticity is, in any case, an impossibly slippery term.

David, you raise an important point which relates to notation - and thank you for your appreciation. A couple of points. Historically, the dark ages and middle ages were synonymous, despite what some 20th century historicans would have us believe. I explain this here. As I explain explain in this article about Kalenda Maya, written music by the 13th century could be read straight from the page in terms of pitch and rhythm, but before then music was largely non-mensural, without written rhythm (with some notable exceptions, such as the Notre Dame school). Secular music before the 13th century in England is now non-existent, and we can be pretty sure this was because of Henry VIII (him again), who was very keen to wipe away all vestiges of Catholicism, burning down and ransacking the institutions which held who knows how many lost manuscripts. By comparison, France has a huge number of surviving troubadour and trouvere songs dating from the late 11th century to the end of the 13th century. Before then, which is your question, we have little beyond a large question mark about European medieval music.

China and India are beyond my field, but I do know someone who specialises in early Chinese music, who may be able to answer your question.