Post History

How do I pronounce historical French correctly from times when the language was in transition?

I sing in a choir that performs medieval and renaissance music in several languages I don't otherwise speak.  When we are unclear about pronunciation, we look for recordings from reputable performers -- but this doesn't always work, and anyway I would like to better develop skill instead of just looking for sources to imitate.  I find French from the 13th through 16th centuries particularly challenging in this regard.

I know that in Old French final consonants tended to be pronounced and some vowels were different.  This [Wikipedia page](https://en.wikipedia.org/wiki/Phonological_history_of_French) (I agree with the annotation that it is confusing and needs attention) describes several periods in the language, including (I think these are nominal end dates):

- Old French, c. 1100
- Late Old French, c. 1250-1300
- Middle French, c. 1500
- Early Modern French, c. 1700

Date ranges for language changes are always going to be approximate and might show regional variation.  It's not like everybody in France woke up one day and said "we're going to do it differently now".  So transitional periods are especially hard to handle.  This comes up for me when looking at 13th- (and even 14th-)century French songs.

When looking at a song (or poem) and deciding on pronunciations, what internal or external clues can I rely on (other than rhymes when they occur, which isn't often)?  By internal I mean: are there signals in the text itself that point to answers?  By external, I mean: do we have better geographic information, so knowing that a composer lived in such-and-such area would point to an answer?