Two (yes, more than one, deal with it) things for you. First the obligatory mass setting, this one by the excellent 14th Century composer
Machaut:
Then a selection of various mostly secular pieces (which I'm guessing is more what you're looking for) ranging from the medieval to the mature renaissance, by an excellent scholar of early music who's represented in my collection (and who makes some remarks along the way), David Munrow:
There's a lot of excellent secular music from the Middle Ages that's been recorded if you look, and it varies widely by region - you might make a list of some of the names and terms (troubadour would be a good one to start with) and work out from there.